1955 Johnson 5.5 CD-12, will it run again?

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

About the Prop,

the 3 pictures below are the sequence of how I put the prop back on.

I got a new cotter pin, (I don't like using the old cotter pins over again) you can pick those up at any hardware store. I installed it first (first picture), then I installed the sheer pin, (second picture) then the rubber cone, (thrird picture)

we're going to get into the subject of a tool box to carry on board when your out on the water running these vintage outboards, I'll go into the full deatails of what I think would be a good idea to have into that tool box at a later time, but this prop brings up a good thought, at least for me.

the sheer pin is held in place by that rubber cone, which means, if you lose that cone, the sheer pin is going with it, and that will leave you stranded out on the water.

I've already started collecting parts to include in my tool box that I will be carrying on board, and part of what I want on hand will be an extra sheer pin or two, but in the case of this particular motor, that rubber cone kind of bothers me, it's as old as the motor, 54 years old, and if it comes off or breaks or something, my fun on the water is done, and I'll be finding myself paddling back to the dock, so I believe it would also be a good idea to carry an extra rubber prop cone in my tool box as well.

luckily, those parts are still avalable, the prop cone is BRP number 0303365, and the sheer pin number is 0302333

next up is the lower unit oil, but I'm going to do a little more internet research before I post my findings, so far I've come across some interesting data, I'll get it all together and then post it, you can decide what's fact, what's myth, what to use, and what not to use.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

[FONT=&quot]When it comes to lower unit oil, an Internet search brings up many varied answers.[/FONT]

[FONT=&quot]I looked up Hi-Vis, Hypoid 90, type C, and a vast combination of other search words such as OMC lower unit oil, OMC oil history, Vintage Johnson Evinrude lower unit oil, lower unit oil myths, just to name a few.[/FONT]

[FONT=&quot]I may be way off base, or I may be correct, the search really left me with more questions then answers.[/FONT]

[FONT=&quot]The one thing I noticed is that oil choice, brand, and type seem to be personal preference, I saw a lot of comments like, ?I use X-brand and type because that?s what the guy at the dealership said to use? or I use X-brand and type because that?s what my neighbor (an avid boater) uses?[/FONT]

[FONT=&quot]I didn?t see anything based on research, it was all based on what ?the other guy? uses, or what ?the other guy told me to use?[/FONT]

[FONT=&quot]Technology has come a long way in 54 years since this outboard was built, back then, they recommended Type C, which as I understand it was OMC?s premium blend, Type C is also what?s used today with the electric shift outboards, whether type C of 1955, and type C of 2009 are the same or not, I don?t know, but apparently you can still get the type C lower unit oil, it?s Sierra part number 18-9620, I don?t know if it?s the same ?type C? as used in 1955, or a newer updated version, my guess is that it?s a newer version, or a version that?s compatible with the older outboards that required the type C.[/FONT]

[FONT=&quot]On in interesting note, I did see some comments on the makeup of the oils used in the 1950?s verses the ones used today that I found somewhat interesting that I?ve never read before.[/FONT]

[FONT=&quot]I don?t know if this is true or not, I can only report what I?ve read, you will have to draw your own conclusions, but supposedly according to one source, the premium blend oil of the 1950?s (type C) used whale oil where the regular blend didn?t, according to what I read, whale oil was used until it was outlawed, Synthetic oils were unheard of at the time, and it took them a while for the ?oil engineers? to come up with a suitable additive to replace the whale oil once it was outlawed.[/FONT]

[FONT=&quot]Now on another note, I read that the Type C used in the electric shift lower units, had nothing to do with the viscosity of the oils, it had to do with the electrical conductive properties of the oil, where the type C was less conductive then the lower grade oils.[/FONT]

[FONT=&quot]Apparently, the lower grade oils had more conductive properties to them then the type C did, and the lower grade oils would interfere with the shift solenoids in the lower units causing them to spike voltage from one solenoid to the other which threw them for loops causing the lower unit to not shift properly.[/FONT]

[FONT=&quot]Bare in mind, when I make that statement, I know nothing about the electo shift lower units, I?ve never owned one, never looked at one, and don?t know a thing about them, I?m only reporting what I read, and my opinion (whether right or wrong) is only another opinion[/FONT]

[FONT=&quot]Now in my mind, after having my lower unit apart, I have the belief that the gears really don?t care what oil is in there, as long as the oil does what it?s supposed to do and keep those gears lubed up, so the theory I read about the electrical conductive properties (or lack of) of the type C oil, makes sense, but without proof, it?s only theory, and some theories make sense, is it true? I don?t know, but you have to admit, it makes sense.[/FONT]

[FONT=&quot]I spent a couple of hours researching the information I found on the net, and the only conclusion I could come to was that type and brand don?t matter as much as making sure your lower unit is sealed and doesn?t leak, on older outboards it?s harder to get the lower units sealed up, (so they say) so change the oil often, as for me, I?m going to use CRC Hypoid 90 (80W90) in mine, not because I feel it?s right , or wrong, but because that?s what I happened to have on hand [/FONT]

 

[tmcalavy]

Re: 1955 Johnson 5.5 CD-12, will it run again?

I believe your motor is F-N-R full shift, but can't remember. Prior to the years after WWII, outboard manufacturers recommended white grease in products without good LU seals, no oil. As outboards went from direct drive to full shift, and seals improved with post WWII technology, they went to marine hypoid oil as a recommendation. I run most all my 50's motors, full-shift, with Lubriplate 105 white engine grease in the LU. You can also use corn head grease from a tractor dealer, if you are in farm country. Neither will emulsify with water, non-displacement, like hypoid oil. Sounds like you made a good, thorough choice.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Thanks for your post tmcalavy,

You?re right, it's F-N-R full shift.

I appreciate your comments about the oil/grease lower unit lube.

The last thing I have to do to the lower unit is to put the oil in it, and will be covering that shortly with photos and thoughts.

Any comments or suggestions from the experts here are greatly appreciated.

Bare in mind as people read this, I am no expert, this is a learning experience for me, and I will be posting what I do and how I do it, regardless if it's right or wrong, I believe any mistakes I make will be typical of the mistakes made by anyone venturing into outboard repair for the first time, so the more knowledgeable people out here are more then welcome to step in and correct me when I'm making a mistake, or if you see an easier way of doing something, I'd appreciate your comments on it.

After we're done with the lower unit, we'll be moving on to the power head, so we have a lot more to do before this motor is running again.

I'm doing internet research on each subject before I do the work for a couple of reasons, 1 - for my own benefit, and 2 - too show what kind of information can be obtained just by taking a little time to sit down and do some searching on the net.

Doing it this way is slowing me down considerably, with taking time to write, take and post pictures, but it's worth it, I want to learn how to do this kind of work, and I want to learn how to do it correctly.

I haven't said a work about the power head yet, but I believe there's some problems with it, and we are going to address those problems, I believe this is going to be typical of any outboard you find and a swap meet, flea market or garage sale where you have no idea of the history, it will kind of give you a heads up of the kinds of things to look out for as you shop for a used outboard.
​

I believe your motor is F-N-R full shift, but can't remember. Prior to the years after WWII, outboard manufacturers recommended white grease in products without good LU seals, no oil. As outboards went from direct drive to full shift, and seals improved with post WWII technology, they went to marine hypoid oil as a recommendation. I run most all my 50's motors, full-shift, with Lubriplate 105 white engine grease in the LU. You can also use corn head grease from a tractor dealer, if you are in farm country. Neither will emulsify with water, non-displacement, like hypoid oil. Sounds like you made a good, thorough choice.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

OK, first off, I don't want to knock my abilities to re-seal the lower unit, but this is my first one, so my confidence is somewhat low as to whether or not I got it sealed up properly, so I'm leaning more towards it leaking then not, but that's ok, if it does leak, we'll get another seal kit and do it again, but for the sake of having to do extra work, I hope it doesn't leak.

Starting with the first picture, I used CRC Hypoid 90 marine lower unit gear lube.

I cut the top off the tube, (second picture) I know, kind of a dumb idea to post a picture of the tube with the top cut off, but oh well.

I then inserted it in the drain hole (lower hole) (see third picture) and squeezed, and watched for the lube to run out the top hole, (see 4th picture)

I then sat there and waiting for it to leak, I know it's going to leak, I couldn't have possibly got it right the first time could I?

ok, I got tired of waiting for it to leak, (so far it hasn't) so I rolled the outboard stand to a clean dry spot in the shop, and decided to let it sit there for a day or so to see if anything does leak out (I?ll be looking for an oil spot on the floor) if I see no leaks, my next "test" is to submerge it in a garbage can full of water and let it sit another day or so, then check the oil to see if there's any water in it.

I figured it's going to be a bit before I get a chance to get it out on the river, and this is the only way I know of, to test it for leakage.

So now that we have the lower unit done (provided it doesn?t leak) we can now start on the power head.
​

 

[tmcalavy]

Re: 1955 Johnson 5.5 CD-12, will it run again?

My shop floor is dotted with small oil spots from "it doesn't leak" lower units. You can check the seals before adding oil/grease by pressuring the lower unit with less than 10 psi of air, I use an improvised bike tire pump and psi gauge, then dip it in water and watch for bubbles or just spray some soapy water around the seals. Sounds like you may have it whipped...are you soaking every bolt/nut/connection on the powerhead with penetrating oil? Makes that chore go a lot easier...that and an impact driver.

 

[freddyray21]

Re: 1955 Johnson 5.5 CD-12, will it run again?

those are good motors, but if they are anythink like the Evinrudes they have a tendency to throw rods. 16:1 on the oil mix or even 12:1. Don't skimp

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Tmcalavy, I was just thinking about a pump for the lower unit last night, I'll either buy one or make one to test it, thanks for your suggestion, I'd like to know that the lower unit isn't going to leak before I put it all back together.

I have cleaned the power head, but haven't soaked any nuts and bolts yet, I don't want to get ahead of myself like I did with the lower unit. I want to be able to take pictures and post as I do the work so you guy's see exactly what I see before I clean things up.

I checked the lower unit today and there's still no oil on the floor, so at this point, it looks like it's not leaking, so the next "test" is going to be to get some air pressure in it and check for leaks. I like your idea of doing that test under water, then look for air bubbles.

Fred, I did read about the rod issue, we'll address that, and I've done some research on the fuel/oil mix, and we're going to address that to (I believe the fuel/oil mix and rod issue are linked). I see a lot of people posting questions about what oil mix to use with their outboard, and while the answers are readily available as to what ratio to use, I'd like to address the issue of why the different years require a different mix, so we're going to discuss that. it's one thing to know what mix you should use, but I also think it's important to know why you should use a particular fuel/oil mix for any given outboard.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

before I get started on pressure testing lower units, I have a quick question, or favor to ask, if anyone reading this has an OMC, Johnson, or Evinrude factory service manual, (or any manual for that matter) that has the word for word, step by step procedure for pressure testing lower units, I'd appreciate it if you would PM me.

we are going to go in depth on pressure testing, I spent a good deal of time searching the internet for information on pressure testing and vacuum testing, and while I didn't find anything at all in regards to what OMC/Johnson/Evinrude had to say about it, I did find plenty of references. so until someone can come up with a word for word "how to" straight out of a factory service manual, all I can do is share what I learned.

as I've stated previously, this is just my opinion, right or wrong, (and I am completely open for correction, so feel free to post)

Before we get started on the actual procedure of pressure testing, we need to have an understanding of how the lower unit is sealed, the types of seals used, and how they will differ in characteristics when pressure tested or vacuum tested.

as in the case of this 5.5 horse, the lower unit consists of 4 different types of seals, we have one gasket, that is located under the water pump, we have 2 O-Rings, one is on the shift rod, the other is on the prop shaft bushing housing, we've got the spaghetti seal, that goes between the skeg and the lower unit, there's also the 2 washers on the drain and fill screws, and there's two seals, 1 is under the impeller, the other is at the end of the prop shaft bushing, plus the gasket sealer used on the skeg when we put it all back together.

so there's seals, o-rings, washers, and a gasket, each one is going to have a different characteristic when pressure or vacuum tested.

so in my opinion, I see a reason to do both a pressure test and vacuum test.

first, take a look at the picture, please excuse my artwork, I'm not good at graphics at all.

the prop shaft seal is angled backwards onto the prop shaft, so air pressure inside the lower unit is going to push the seal into the shaft, vacuum is going to pull it away from the shaft (to a degree), it is probably the single most important seal that could cause you trouble on a lower unit.

this particular motor is 54 years old, so who knows what's been wrapped around the prop shaft over the years, the biggest complaint I've read about is getting debris wrapped around the shaft like fishing line ect, and have it ware a groove into the shaft whereby causing the seal to leak, and installing a new one wouldn't help that situation at all, actually, the original seals and the new replacements that come in the lower unit seal kits these days are quite different whereas the old ones didn't angle backwards like the new ones do, and they had more surface area riding on the shaft.

the O-Rings I believe are going to show the same characteristics whether they have pressure or vacuum applied against them, just the same as the flat gasket under the water pump, and the fill and drain screw washers, I don't believe it will make a difference with the spaghetti seal or gasket sealer either, but doing a pressure test or vacuum test with the two seals will. The seal under the impeller is constructed just like the one on the prop shaft.

I believe the lower unit is designed to have pressure in it, although it's very little, it's enough to keep the seals closed and the water out, that's why we only pressure test to 10 to 15 PSI, but we're going to get into that later.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

My next step is to come up with a pressure tester, my goal here is to build something low cost, and simple, so I did a google search for "lower unit Pressure tester" and came up with a few pictures, and I decided to go with the simplest one I could work with, the first picture is a pressure tester available on the internet for about 130 dollars, the second picture is one I made for less then 20 dollars.​

the third picture is the gauge I got for it, it came off ebay, total price shipped to my door was 3 bucks for the gauge, those gauges can be had really cheap on ebay, their all over the place, just do a search for "npt pressure gauge"​

I went with 3 and a half feet of 1/4 inch fuel line hose that's rated to 50 PSI, I figured that would give me the length needed to bring the gauge out of the test tank should I decide that I want to dunk the lower unit and look for leaks, (or bubbles in the water)​

I felt that the simplest design would yield the least amount of trouble, so I kept it very simple with the fewest connections as possible, I used a ball valve between the gauge and the air source so once I had the lower unit pumped up to 15 PSI, I could close the ball valve and disconnect the tester from the air source.​

for the connector that screws into the drain or fill plug on the lower unit, I used a metal fitting off a lower unit oil pump, make sure that fitting it metal, plastic won't work, the metal ones have an O-ring on the end of them that positively seals them into the lower unit, you can buy those just about anywhere that sells boating supplies.​

I also used a quick disconnect fitting that fits my air hose off my air compressor, with the regulator built into the air compressor, plus the ball valve on the tester, you can be very precise with your pressure settings.​

I chose to use a little airbrush compressor I have to supply air, (see 4th picture)
The benefits of it are: it?s got a built in pressure regulator, it builds pressure slowly, It?s small and light, and I?ve found many uses for it other then supplying air to this tester.​

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

For the purpose of supplying air to your tester, there are many options; the bicycle pump seems to be the most popular, but I feel there?s better options out there then a bicycle pump, Harbor freight sells a siphon pump, that does both vacuum and pressure, (item number 3878-5VGA) and it?s only 6 bucks, it?s easily adapted to our application with this tester (see picture)​

The nice thing about the siphon pump is it will give you the best of both worlds, with a Vacuum/pressure gauge you are now able to do it all with one tool. The gauges are easily found through sources like ebay, and their pretty inexpensive.​

Had I known this when I built mine, I would have bought a vacuum pressure gauge instead so I had it all in one tool.

Regardless of what you choose to use for an air source, it?s imperative that your test instrument does not leak, a faulty test instrument is going to give you false readings on your lower unit, I found with the pressure tester I made that I had a few leaks, and when I tried it for the first time, the lower unit failed the pressure test miserably, my first thought was, ?darn it, I messed up the seal kit installation? but then I took the tester, and dunked it in a bucket of water while under pressure and found I had a few leaks, once I got everything tightened up, and the tester wasn?t leaking anymore, the lower unit passed the test. So if you build one of these, before you use it, make sure it?s not leaking. Any connection, seal, or seam, has the potential to leak, that?s why I made this tester as simple as possible, to eliminate any potational problems with leakage.​

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Lets get down to actually pressure testing the lower unit, I had a little trouble with this one, not that pressure testing is a hard job, it?s really very simple, but getting the correct information seems to be a challenge.

Through all the internet searching I did, is seems as though that there?s no real set standard on a pressure testing procedure, everyone seems to be in agreement on the amount of pressure you should use, I read anywhere from 10 to 16 PSI, that seems to be the average across the board on lower units no matter what make your outboard is, where I saw some serious discrepancy was in the amount of time the lower unit should hold a set pressure, I saw anywhere from ?a few minutes? to 24 hours, and every conceivable length of time in between, what I found interesting was people would ask the basic question, ?how do I pressure test my lower unit?? and they got all sorts of responses with replies like ?this is how I do it? I came to the conclusion, that if you asked 6 different people ?how do you do it?? you would get 6 different answers, I think the end result is the same, but how you go about testing it seems to vary, what I found funny was seeing some questions like, ?what?s the acceptable pressure loss over a given period of time?? with that question, the comments and replys stopped, which lead me to believe that no one really knows.

My goal here is to do a complete lower unit pressure/Vacuum test and leave nothing to question, so in this case, we need a standard set procedure to follow, but with out finding one on the internet, or in any of the manuals I have it leaves me the challenge of coming up with my own SOP (standard operating procedure) so I?ll say it again, this is only my personal opinion, and how I?m going to go about testing my lower unit.
whether I'm right or wrong, this is how I do it. and I'm always open to correction, so if anyone wants to chime in here please feel free to do so.​

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Lets get down to the actual lower unit pressure test.​

This is how I came up with the criteria for this test, I did some extensive internet searching and jotted down all the numbers I could find in regards to pressure testing lower units, some numbers were pretty consistent, other were all over the place, I took the most frequently repeated numbers and decided to use those. So below is the list and sequence of the test preformed (in my opinion) of how it should be done, I will come back and edit this if someone can provide word for word out of an OMC manual how the manufacture recommends doing it, in the mean time, this is the conclusion I?ve come to.

_____________________________________________________________​

LOWER UNIT PRESSUR TEST

This consists of two tests, a low-pressure test and a high-pressure test.​

Test (1) Low-pressure test
1 ? drain the lower unit oil
2 ? attach your pressure checker tool; you can use the bottom hole or the top one.
3 ? apply 6 lbs of pressure to the lower unit
4 ? wait 45 minutes, and check pressure reading.
You should not lose more then 2 pounds of pressure in a 45-minute period
5 ? release pressure​

Test (2) High-pressure test
1 ? apply 15 lbs of pressure to the lower unit
2 ? wait 45 minutes, and check pressure reading.
You should not lose more then 3 pounds of pressure in a 45-minute period.
3 ? release pressure.​

In both tests, you can dunk the lower unit in a barrel of water so the impeller is below the water line and look for bubbles to determine where a leak may be coming from, or if you have a good ear, you can listen for air leaks.​

If the lower unit does not pass this test, seals will need to be replaced.​

______________________________________________________________

The reason for the two tests is because doing a low pressure test does not put much pressure against the two seals (drive shaft and prop shaft) so if one or both of the seals has been weakened through use or age, the low pressure test is more likely to show a defect.​

The high-pressure test forces the two seals against the prop shaft and drive shaft, putting more pressure against the O-rings, spaghetti seal, gasket, and gasket sealer, so you can determine if they may be faulty.​

I may have gone a little over board with this (no pun intended) but I want to be sure I was thorough and didn?t leave anything to question, for any reason anyone sees any errors in this method, please post or let me know.​

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Just for the record, when I pressure checked this lower unit, I pumped it up 15 lbs of pressure and walked away from it for 12 hours, when I finally came back to check the readings, it had dropped to 13 lbs of pressure, so I lost a total of 2 lbs in 12 hours, when I checked it at 6 lbs, I walked away for about 5 hours and when I came back to check it, I had lost about a half pound of pressure. but I can't say for sure if the pressure was lost through the lower unit, or through the gauge tool, the loss was so little, I never saw any bubbles when I dunked the lower unit in a bucket of water, so as far as I can tell, the loss could have just as easily been in the pressure checker tool instead of the lower unit, but either way, with those readings, I'd say the lower unit passed the test.

next up is the vacuum test, and the tool used to do it, I've had a harder time finding info on vacuum testing, I found there's very little information on the internet about it, but I did find some, so we're going to go into Vacuum testing next​

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

lets address the Vacuum test.

this test isn't as involved as the pressure test is, not that either one is difficult to do, but there is less to the vacuum test.

when I started this thread, I really didn't think a Vacuum test was all that important, then I got to reading about it on the internet and found that it is as important as pressure test, allow to to share a story I read, this is what convinced me a Vacuum test needs to be done along with the pressure test

as the story goes, there's this guy that has oil occasionally dripping from his lower unit on the garage floor, he changes his oil ever few months and finds traces of water in the oil, he takes his outboard in for a pressure test and it passes, they determine that there's nothing wrong with his lower unit and it must be condensation causing the water to mix with the oil, but it occasionally still drips on his garage floor, not satisfied with the test results from his mechanic, he decides to do a Vacuum test. it failed the vacuum test.

remember back a few posts when we talked about the prop shaft and drive shaft seals and how they are built, applying pressure inside the lower unit forces those seals against the shafts, sealing off any potential leaks, when you do a vacuum test, it pulls against those two seals, instead of pushing them into the shafts, if those seals are weakened, this is when the defect is going to show up, as was the case with the guy that had the drips coming from his lower unit, when he pressure tested it, he forced those seals against the shafts and the leaks stopped, when he vacuum tested it, it pulled against the seals and caused the prop shaft seal to leak, once he re-sealed his lower unit, the problem was gone. But that problem didn't show itself clearly until he preformed a vacuum test.

Vacuum testing is fairly simple, and the tools needed to preform the test are inexpensive.

I still need to refine my tools for this test, I wanted to get the tool built and the test out of the way tonight so I kind of did it quick and dirty, I still need to refine the tool, but it worked fine as it is.

the first picture is of the vacuum tool, and vacuum pump. the tool is identical to the pressure test tool, except it's got a vacuum gauge in it instead of a pressure gauge, the ideal tool would be one that has a vacuum/pressure gauge and had I been thinking when I built mine, I would have used that type of gauge so I could use the same tool for both tests.

the pump is a simple brake bleeder vacuum hand pump found at harbor freight for about 10 dollars, it's capable of pulling about 27 inches of vacuum, so it works perfect for our needs.

here's the specks for the Vacuum test:
________________________________________________________________

VACUUM TEST

1 - Drain lower unit oil
2 - insert vacuum gauge tool into either hole
3 ? Pull 10 inches of vacuum from the lower unit
4 ? wait 45 minutes, and check vacuum reading.
You should not lose more then 2 inch of vacuum in a 45-minute period
5 ? release release vacuum

________________________________________________________________

when I vacuum tested this lower unit, I lost about a half inch of vacuum over a period of about 45 minutes, so I'd have to say that this passed the vacuum test.

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

That about wraps it up for the lower unit, there is one more "test" we could do that would check to see if the impeller is pumping water and if it's pumping the volume it's supposed to pump.

I've read about people using a 1/2 inch drive cordless drill on the drive shaft to turn it and make it pump water, but I don't have a 1/2 inch cordless drill, I have a half inch corded one, and I' not so sure I want to attached a corded drill that close to the water tube and have water pumping out all over my drill, that could prove to be a shocking experience.

it looks like we're about ready to move on to the power head

 

[Mr.Stuart]

Re: 1955 Johnson 5.5 CD-12, will it run again?

Just a quick update:

I finally found the pressure test procedure in a manual.

This comes out of the Clymer Evinrude service and repair handbook 1.5 to 35 HP, 1965 to 1978, chapter 7, lower unit, towards the end of the chapter.

Clymer?s version is very simple:​

• Remove drain plug and insert pressure gauge​
• Pump pressure up to 16-18 pounds​
• Check for leaks at gasket mating surfaces and seals.​
• Pressure will gradually drop after a minute or so, which is normal.​
• If any one seal needs replacement, chances are the others will soon follow. If one seal is replaced, do the whole set to eliminate repeating this same job at a later date.​

 

[auglaizewader]

Re: 1955 Johnson 5.5 CD-12, will it run again?

This rebuild looks like it is going well for you. I have a similar motor. '55 5.5 johnson. Mine runs very well. I understand you aren't an expert, but what is the little panel below the top plug for the lower unit oil? Yours has 2 holes, but mine has 4. I am leaking a small amount of oil around the outside of that panel. Any ideas?