PortlandTom

I just received a PSD pump that I bought on eBay. When it arrived, the carton it was in was disintegrating because brake fluid leaked from the pump. I checked the unit over carefully, and the only thing I could see wrong was the green module with the six pin electrical connector seems to be cocked toward the back - see picture below.

If these things weren't so hard to find, I would just send it back for a refund. However, I'd like to see if there's a way to salvage it.

Does anyone know enough about these things to know if there is a problem here? Does the module (I assume its a pressure sensor) screw out of the pump? Are spare parts available for these units? Does anyone in the US services these things? (I found a link to a place in the UK.) Anyone have a service manual for the pump?

Thanks for any help you can provide.
Tom
'93 GTS, 5 speed, Amazon Green

SeanR

From that picture it looks like the casing is broken......correct?

Shoot some more pictures for us.

RyanPerrella

hard to identify what part of the pump that is honestly, maybe take some more pics

AO

Why not fill it up and pressurize it? You'll find out if it's bad...

Mrmerlin

from the picture it looks like the green part screws into the alu part and it also looks like it is straight. You could try to unscrew it to verify the threads

RyanPerrella

what line should be disconnected to remove one of these pumps safely?

I am worried about the supposed 1 billion PSI of the accumulator but i think that goes only to the block which then reduces pressure through the line and into the slave cylinder. Can i just break into the line after this block to pull the PSD unit for testing?

AO

I'm pretty sure you would want to de-pressurize the accumulator - as if you were bleeding it, but disconnect the pump so it doesn't re-pressurize.

RyanPerrella

ok so disconnect the pump's power and bleed the accumulator from the valve block, then break into the line to the slave cylinder?

PortlandTom

OK, here are more pictures. Hopefully they give a better idea of what I'm talking about.

SeanR - I can't find any cracks in the casing, but the green piece is definitely cockeyed.

Andrew - I'm not sure I want power it up because of the pressures involved. When I know a little more about what's going on, I may try that.

Mmerlin - The green piece is definitely not in straight. It's hard to get a picture to show that because of all the other stuff around it, but it's pushed toward the back.
My thought was that it screws in too. I just want to verify that's the case before I try it.

Ryan - I saw in a previous thread that you have a copy of the service manual for this thing. Could you send it to me? Is it in electronic form?

thanks,
Tom

AO

That's got to be the pressure sesnor. How does it compare to your old one?

Well you're going to have to pressurize it eventually - just aim it away from you.

RyanPerrella

Tom,

The service information that was sent to me is ok. Its only about 8 pages. However the factory WSM has about 50 pages on the PSD system alone and is a much much better read on the ins and outs of the PSD. Check your WSM, or purchase one from one of the sponsors. I would suggest only the WSM for PSD work, it is pretty comprehensive in my mind.

PortlandTom

Well, I decided to try to remove the pressure switch. I expected it to be bent when it came out, but it's straight and apparently undamaged. It looks like the switch is supposed to be crooked relative to the pump housing. Strange!

I didn't realize the switch was supposed to be cockeyed, because I didn't have anything to compare it with. The original pump on my GTS disappeared sometime in the unknown past.

So now I'm hopefull that the whole unit is OK. Tomorrow, I'm going to try pressuring it up.

Thanks for all the info.
Tom

steaditim

I searched high and low for someone in North America that can service the PSD unit.

Could not find anyone !

I did get referred to a place in the UK. I shipped my unit the them about a month ago.

I let you know how it turns out.

Tim

PortlandTom

OK, so I installed the PSD pump, and it seems to be working fine. The motor runs, builds up pressure and stops after 30 seconds or so. No leaks.

Since the slave cylinder and line back to the pump have been on the car unused for a long time - at least five years - I decided to remove them and check them over. I found a bunch of thick, rust-colored gunk in the valve in the middle of the line. Not sure if it's congealed brake fluid, rusty metal, or what. Solvent cleaned it all up, so I think that will be fine.

Found a little bit of the same in the slave cylinder, and the piston was frozen in place. Let it soak in Liquid Wrench overnight and the piston came out with air pressure. I was able to clean everything up in the cylinder as well. However, two of the three o-rings on the piston are cracked. I probably would have replaced them anyway, but now it's necessary.

Anybody know where to get replacement seals? Or what the part numbers are, at least? I found a list of seals for the manual transmission in the PET, and found two that seem to be differential-related (928.332.xxx.xx seem to be differential parts), that don't match any parts called out in the differential diagrams - 928.332.215.02 and 928.332.217.02. Could they be one of these?

Also, do the bellows (rubber part that goes over the end of the slave cylinder that goes into the differential) just pull out? I tried to get mine out to inspect it, but it didn't want to come out. I'd still like to get it out, but don't want to tear it.

Here is a picture of the disassembled slave cylinder. Is this the same as the inside of the clutch slave?

TIA,
Tom

SeanR

Rog at 928'srus should be able to source them for you.