Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Question for PSD pump experts

Thread Tools
 
Search this Thread
 
Old Jun 10, 2008 | 12:05 AM
  #1  
PortlandTom's Avatar
PortlandTom
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Sep 2002
Posts: 209
Likes: 15
From: Portland, OR
Question Question for PSD pump experts - Now Slave Cylinder Rebuild

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
Attached Images
File Type: jpg
PSD Connector.JPG (136.6 KB, 539 views)

Last edited by PortlandTom; Jun 21, 2008 at 12:46 AM. Reason: Changed topic to PSD slave cylinder rebuild
Reply
Old Jun 10, 2008 | 12:13 AM
  #2  
SeanR's Avatar
SeanR
Rennlist Member
 
Joined: Apr 2006
Posts: 35,695
Likes: 511
Default

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

Shoot some more pictures for us.
Reply
Old Jun 10, 2008 | 12:19 AM
  #3  
RyanPerrella's Avatar
RyanPerrella
Nordschleife Master
20 Year Member
 
Joined: Apr 2006
Posts: 8,936
Likes: 3
From: theporscheconnection.com
Default

hard to identify what part of the pump that is honestly, maybe take some more pics
Reply
Old Jun 10, 2008 | 09:04 AM
  #4  
AO's Avatar
AO
Supercharged
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 18,926
Likes: 88
From: Back in Michigan - Full time!
Default

Why not fill it up and pressurize it? You'll find out if it's bad...
Reply
Old Jun 10, 2008 | 10:49 AM
  #5  
Mrmerlin's Avatar
Mrmerlin
Team Owner
20 Year Member
 
Joined: May 2004
Posts: 31,239
Likes: 4,223
From: Philly PA
Default

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
Reply
Old Jun 10, 2008 | 12:17 PM
  #6  
RyanPerrella's Avatar
RyanPerrella
Nordschleife Master
20 Year Member
 
Joined: Apr 2006
Posts: 8,936
Likes: 3
From: theporscheconnection.com
Default

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?
Reply
Old Jun 10, 2008 | 12:34 PM
  #7  
AO's Avatar
AO
Supercharged
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 18,926
Likes: 88
From: Back in Michigan - Full time!
Default

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.
Reply
Old Jun 10, 2008 | 12:39 PM
  #8  
RyanPerrella's Avatar
RyanPerrella
Nordschleife Master
20 Year Member
 
Joined: Apr 2006
Posts: 8,936
Likes: 3
From: theporscheconnection.com
Default

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

The Best Porsche Posts for Porsche Enthusiasts

story-0

2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

 Joe Kucinski
story-1

Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

 Verdad Gallardo
story-2

9 Vehicles Porsche Helped Engineer that Aren't Porsches

 Verdad Gallardo
story-3

9 Features and Characteristics That Only Porsche People Understand

 Verdad Gallardo
story-4

I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

 Joe Kucinski
story-5

10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

 Verdad Gallardo
story-6

Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

 Joe Kucinski
story-7

This Builder Is Turning Heads With Its Slantnose 911 Creation

 Verdad Gallardo
story-8

Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

 Verdad Gallardo
story-9

Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

 Verdad Gallardo
Old Jun 10, 2008 | 03:24 PM
  #9  
PortlandTom's Avatar
PortlandTom
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Sep 2002
Posts: 209
Likes: 15
From: Portland, OR
Default

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
Attached Images
File Type: jpg
PSD1.JPG (146.2 KB, 572 views)
File Type: jpg
PSD2.JPG (24.1 KB, 568 views)
Reply
Old Jun 10, 2008 | 04:11 PM
  #10  
AO's Avatar
AO
Supercharged
Rennlist Member
20 Year Member
 
Joined: May 2002
Posts: 18,926
Likes: 88
From: Back in Michigan - Full time!
Default

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

Originally Posted by PortlandTom
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.
Well you're going to have to pressurize it eventually - just aim it away from you.
Reply
Old Jun 10, 2008 | 04:53 PM
  #11  
RyanPerrella's Avatar
RyanPerrella
Nordschleife Master
20 Year Member
 
Joined: Apr 2006
Posts: 8,936
Likes: 3
From: theporscheconnection.com
Default

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.
Reply
Old Jun 11, 2008 | 04:32 AM
  #12  
PortlandTom's Avatar
PortlandTom
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Sep 2002
Posts: 209
Likes: 15
From: Portland, OR
Default

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
Reply
Old Jun 11, 2008 | 09:40 AM
  #13  
steaditim's Avatar
steaditim
Rennlist Member
 
Joined: Oct 2003
Posts: 230
Likes: 0
From: toronto
Default

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
Reply
Old Jun 21, 2008 | 12:44 AM
  #14  
PortlandTom's Avatar
PortlandTom
Thread Starter
Rennlist Member
20 Year Member
 
Joined: Sep 2002
Posts: 209
Likes: 15
From: Portland, OR
Default Slave Cylinder Rebuild

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
Attached Images
File Type: jpg
Slave Cylinder.jpg (30.8 KB, 1223 views)
Reply
Old Jun 21, 2008 | 12:48 AM
  #15  
SeanR's Avatar
SeanR
Rennlist Member
 
Joined: Apr 2006
Posts: 35,695
Likes: 511
Default

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



All times are GMT -3. The time now is 06:07 AM.

story-0
2026 Porsche 911 Club Coupe is Spectacular, And Everything Wrong with the Porsche Market

Slideshow: The 2026 Porsche 911 Club Coupe is being resold $150K above sticker and that is a real problem.

By Joe Kucinski | 2026-05-21 11:52:54


VIEW MORE
story-1
Talos Takes Your 991 Porsche 911 GT3 to the Next Level for a Cool $1.13 Million

Slideshow: Talos Vehicles has transformed the Porsche 911 GT3 RS into a carbon-bodied, race-inspired machine that costs well over $1 million before the donor car is even included.

By Verdad Gallardo | 2026-05-19 13:39:04


VIEW MORE
story-2
9 Vehicles Porsche Helped Engineer that Aren't Porsches

Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.

By Verdad Gallardo | 2026-05-15 12:44:44


VIEW MORE
story-3
9 Features and Characteristics That Only Porsche People Understand

Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.

By Verdad Gallardo | 2026-05-13 18:46:13


VIEW MORE
story-4
I've Written 500 Rennlist Articles: Here's How Porsche Has Changed Along the Way

Slideshow: Six years and 500 Rennlist articles later, these are the biggest changes at Porsche.

By Joe Kucinski | 2026-05-11 09:52:55


VIEW MORE
story-5
10 Most Unnecessary Porsches Ever Built (And Why We Love Them)

Slideshow: Some Porsches exist for very specific reasons-others feel like they were built just to see if anyone would notice.

By Verdad Gallardo | 2026-05-06 18:00:32


VIEW MORE
story-6
Porsche 911 GT3 S/C vs 718 Spyder RS: 10 Categories, One Winner

Slideshow: Choosing between the 911 GT3 S/C and 718 Spyder RS in 10 key categories to determine one surprising winner.

By Joe Kucinski | 2026-05-05 12:51:46


VIEW MORE
story-7
This Builder Is Turning Heads With Its Slantnose 911 Creation

Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.

By Verdad Gallardo | 2026-05-01 10:49:43


VIEW MORE
story-8
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture

Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.

By Verdad Gallardo | 2026-04-28 19:37:40


VIEW MORE
story-9
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look

Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.

By Verdad Gallardo | 2026-04-27 19:39:30


VIEW MORE