SLS pump rebuild - done
 

More or less an FYI thread for those doing this.

I tried to rebuild the SLS pump last winter (maybe two winters ago). I ran into an issue with the o-rings. I bought sizes in standard suggested here, I could not locate metric. ******** does not sell the kit anymore. Issue was the slightly increased thickness. This causes the cam to slide too far forward allowing the interface in back to grind against the pump casing. I took it all apart and put the old ones back in.

Been living with a leaking system since then.

Today I took another stab at it. I used the same sized o-rings, but needed to compensate for the cam being able to now move forward nearly 2mm. I had no way to shift the bushing in the front "cap" of the pump outwards (back). So I crated a "shim" using a large flat washer. I used my Dremel to increase the inside diameter for a tight fit over the cam. I then ground the leading edge to create a bevel for the pistons to move under. Without the bevel there may be a chance for the washer to slide down in front of a piston head and jam it all up. This worked great. But the washer was a tad too thick. When I put it back together, I could not move the pump by hand. To fix this I ground the bushing and even some of the casing off the inside front cover (see pic). Now when tightened up there was just a slight amount of play. You do want a little to prevent any binding as all the bolts are installed when putting it back in.

So far so good. Took her for a drive, revved things up a bit and now no leaks. I will park in a new spot at work in the morning to see if I can find a spot on the ground. I would leak about 1 quart every week or two.

Really the correct size of the three o-rings may prevent any issues. I also think my pump was very, very worn. The original o-rings were cracked and very flattened out. But if you rebuild yours, make sure the cam does not have too much play. Also, don't forget the banjo bolt gets TWO copper washers an each side of the hydraulic line. I forgot one on the first attempt and it leaked all over.

What is an SLS pump rebuild?

Where is it located?

Thy hydraulic suspension pump located at the front of the engine.

I rebuilt mine a couple/few years ago. I got all the seals for $45 from

Perfanalysis@comcast.net

I found it quite a bit easier than hunting around and trial and error. Just my $.02

My pump has been running dry for at least 100 miles. (I just bought the car).

There was a leak in the lower hose (I'm pretty sure) which sprayed gunk all over that area including the pump.

My questions:

(1) does it matter if there is grime on the outside of the pump?

(2) what are the chances that it having run dry has damaged the pump?

I may end up rebuilding the pump anyway but my fingers are crossed its just the hose.

Grime is not an issue as far as I am aware. It's a sealed system so there are no holes or anything where contaminates can access the fluid.

If you run it dry I think you can damage it. It has metal parts that rub against each other. With no hydraulic fluid to lubricate it I would think it could cause friction and wear that would damage the pump.

I ran mine dry a lot. Not intentionally, just really got sick of adding fluid. I noticed by design its pretty hard to run 100% dry. I always had some fluid at the bottom of the tank. But I would not recommend it.

By the way, the hose should be a very specific part. I picked up a Gates brand section of hose. Still need to install it but I think mine was replaced once already. I don't have the link, but the hose MUST be able to handle the pressure!!!!

Was taking apart the pump pretty foolproof? Trying to get it done in a weekend once my seal rebuild kit arrives but I see very little info out there on doing the rebuild. I drive the car everyday, so I'm just making sure I don't get caught with my pants down once the work week rolls around.