SX-A Trim Pump Inop (Not a Cover Problem)

[skydiveD30571]

Reading all the threads last year about the original SX-A trim pump cover leaking, and ThreeMileBayWaker's awesome DIY thread, I had a strange feeling all last year that I would soon have trim trouble. Well it started yesterday, but it's not a leaking cover.

When I stored the boat over the winter, I put the drive down to about 2" from the ground. I would check on it about once a month over the winter and each time the drive had dropped down to the ground. Last week I put the battery in to raise the drive and tow home for some spring cleaning. Nothing abnormal with trim operation. Took it back to storage and this time left it up so that I could monitor droppage levels. A couple days later I came back expecting it to be on the ground and it wasnt. Not all the way up, but mostly. A week later I went to storage and the drive has dropped significantly....about 2/3 down now.

With plans to tow home again, hooked the battery up and hit the trim up button. I can hear an obvious high pitched whine that I believe to be the electric motor in the trim pump (I have no idea how these actually work) but that normal, deeper, louder tone of the hydraulic pump is gone and of course the drive goes nowhere. Not up or down. The pump cover has never leaked, and although the trim cylinder ends have shown a small amount of liquid here and there (less than a drop) for a couple years now, I didn't expect a low fluid scenario. But just to be sure I added some and tried again. No dice. I also can't lift or push down the drive which makes me believe fluid levels are ok.

It sounds to me like a shot pump, but of course Volvo doesn't sell the pump on it's own, but instead the whole trim pump assembly which is $900. I DON'T NEED THE COVER AND NEW LINES TOO! Before I fork that out, I plan to take this one apart and see if I can tell what's going on. Does anyone have experience with trim pumps, how they operate, or what would cause the motor to run and not the pump? How about having a local hydraulic shop take a look at it?

How about a way to release pressure before taking the pump out since I can't trim down?

 

[Bondo]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Reading all the threads last year about the original SX-A trim pump cover leaking, and ThreeMileBayWaker's awesome DIY thread, I had a strange feeling all last year that I would soon have trim trouble. Well it started yesterday, but it's not a leaking cover.

When I stored the boat over the winter, I put the drive down to about 2" from the ground. I would check on it about once a month over the winter and each time the drive had dropped down to the ground. Last week I put the battery in to raise the drive and tow home for some spring cleaning. Nothing abnormal with trim operation. Took it back to storage and this time left it up so that I could monitor droppage levels. A couple days later I came back expecting it to be on the ground and it wasnt. Not all the way up, but mostly. A week later I went to storage and the drive has dropped significantly....about 2/3 down now.

With plans to tow home again, hooked the battery up and hit the trim up button. I can hear an obvious high pitched whine that I believe to be the electric motor in the trim pump (I have no idea how these actually work) but that normal, deeper, louder tone of the hydraulic pump is gone and of course the drive goes nowhere. Not up or down. The pump cover has never leaked, and although the trim cylinder ends have shown a small amount of liquid here and there (less than a drop) for a couple years now, I didn't expect a low fluid scenario. But just to be sure I added some and tried again. No dice. I also can't lift or push down the drive which makes me believe fluid levels are ok.

It sounds to me like a shot pump, but of course Volvo doesn't sell the pump on it's own, but instead the whole trim pump assembly which is $900. I DON'T NEED THE COVER AND NEW LINES TOO! Before I fork that out, I plan to take this one apart and see if I can tell what's going on. Does anyone have experience with trim pumps, how they operate, or what would cause the motor to run and not the pump? How about having a local hydraulic shop take a look at it?

How about a way to release pressure before taking the pump out since I can't trim down?

Ayuh,.... I don't do Volvos, so I'm shootin' from the hip,....

iboats sells trim pumps,... replacement aftermarket,... decent quality, probably on par with OEM,...
Donno how much they are, but I'm bettin' it's well under $900.00....

Buy one, 'n plumb it into place of whatever ya got now,...

To release any pressure, just fine a spot to crack the lines loose,...
Put a catch pan under wherever that is, cause there's gonna be oil loss,...
Probably at the cylinders, but again, I don't do Volvos,...
Maybe at the pump, with Lotsa rags,...
Yer lookin' at 'bout a quart or so,...

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Thanks Bondo. A friend of mine said his dad's trim got stuck up once and they cracked one of the lines loose and the drive began to fall. From there they bled the system and topped off the reservoir and all was good. It's worth a shot. It's just strange that the electric motor is running but not the pump...I have yet to find another thread with the same problem. Seems like when pumps go bad, its the electric motor that is generally at fault.

 

[Bondo]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Thanks Bondo. A friend of mine said his dad's trim got stuck up once and they cracked one of the lines loose and the drive began to fall. From there they bled the system and topped off the reservoir and all was good. It's worth a shot. It's just strange that the electric motor is running but not the pump...I have yet to find another thread with the same problem. Seems like when pumps go bad, its the electric motor that is generally at fault.

Ayuh,.... It could be just stuck internal valving,...

Have a fat friend Jump on it with the motor runnin' Down,...

You should Never run it Up against the stop/ overload, 'n leave it,...
Just tap the down button a few times to unload the valves,..

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

That's what we're hoping!

A couple notes on this, it might not matter. In the 3 years of owning this boat, it was either stored down over winter, or I would run it up to the stop, insert the trailering clips over the rams, and tap the drive down a couple times until it was seated on the clips. The trip before this happened was the first time I've ever trailered with the drive in the full up position and without the clips, and left the drive in the full up position. We'll see...

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Resolved. I guess I can be called an idiot for making assumptions, but this was kind of weird so here it goes anyways.

FYI to those with an sx-a trim pump, of the two allen head screws on the front of the pump, the right one is a pressure relief. Just crack that open to relieve the pressure in the system without cracking lines.

Did that, drive came down, still no pump. Took the cover off and fluid went everywhere. That stuff is a pain to work with...makes everything slicker than snot! Couldn't get the pump out due to the wiring that goes thru the transom so I crawled into the engine compartment to find a way to disconnect it. My boat has a ground bus at the aft starboard corner of the engine compartment, which I hook to the battery in the offseason to run aux stuff like lights, etc. I realized the engine block ground was unhooked but seeing as ground is a common, I couldn't imagine it mattering. But just for giggles I hooked it up too and of course...I hear the pump fire and gurgle whatever fluid is still in it. Put everything back together, filled and bled the system, works like a champ now. Since the motor/pump is one unit with one ground wire coming from it, I have no idea why the pump only works with the engine block ground attached, but that's how it is. My only guess is the pump's higher current draw cannot be supported by the ground bus??

Anyway, for future reference, make sure ALL grounds are hooked up. The reason I skipped this is because when I heard the electric motor spinning I instantly assumed it cannot be an electrical problem since the motor is spinning. You know what they say about assuming....

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Lovely, now I have a trim pump leak. Noticed when I got to the lake friday evening that the trim pump had fluid around it. I had a hard time filling the reservoir so I figured it was just spilled fluid. Pulled the boat out saturday evening and I have a milky mix leaking from the right hand bolt (part #6 below). No leaks from the white plugs. According to diagrams, there is no o-ring here and I never saw one while taking the pump apart. Not sure why it isn't sealed now, or how to seal it. It leaks out at a pretty good rate (1 drop every 30 seconds or so) so I'm guessing this is the sight of water intrusion too.



This is the sx-a trim pump first design, as I haven't bought the new cover since I've never had a leak before. For those of you that took this pump apart or replaced the cover, have you had any trouble with this? Also I need to drain the reservoir and get all the watery fluid mix out of the system...how can I do that?

 

[Thalasso]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Part #6 ?

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

My fault I forgot the attachment. It's huge on my computer so I'm not sure why iBoats uploads it as a tiny picture now.

 

[skydiveD30571]

Re: SX-A Trim Pump Inop (Not a Cover Problem)

Bumping for suggestions on bleeding out the milky fluid.

I've read that some people empty the reservoir and pump, refill it, run it a few times, rinse and repeat a couple times and call it good.

I've also read that you should empty the reservoir and pump, take the cylinders off and pump them by hand to remove the oil inside, blow the lines out, put together and run a few times.

 

[skydiveD30571]

I forgot a closing comment for future readers. I went with option #2. Emptied reservoir and pump, unhooked trim lines and manually pumped trim cylinders rams back and forth until no more fluid was coming out of lines. There's 4 o-rings inside of pump cover and apparently I pinched and tore one with the #6 bolt as I was installing everything the first time. Went to the local hardware store and found a reasonably identical o-ring, assembled everything, filled with fluid and ran the system repeatedly. Problem fixed and $900 saved.

When the SX-A pump is reassembled, it is important to remember to bolt the cover to the pump BEFORE bolting the cover to the transom. That's where I messed up. If that is done, it is a straightforward assembly.

 

[Saltydog316]

skydiveD30571, how did you empty the reservoir and pump? Did you have to remove the assembly cover and disconnect the line running inside the hull? Anyway to do it without removing the assembly? Thank you.

 

[skydiveD30571]

Hi Saltydog, as this thread is over a year old it is usually best to start your own thread. That way you'll get more responses from the usual members. To answer your question, removing the pump and reservoir and tilting it upside down drained it fine. The cover has to come off to get to the pump yes. The line running inside the hull is the electrical wiring and it can be unplugged at the pump.