DWS964

I backed the car out of the (clean) garage tonight, and saw a small puddle of Blue brake fluid from under the rear of the car. Now, the last time I flushed the brakes, ABS accumulator, and clutch was with Ate gold on Oct 30. I did not do my PDAS diff locks that time. The previous system flush/bleed was with Ate Blue. Thus, I knew this had to be a diff lock problem.
I can see leakage around the mounting flange of the lock cylinder. The question is - is there a seal barrier that is keeping this fluid out of my diff/trans fluid? My brake fluid resevoir has not gone down much, so that is the "good" news. I cleaned up the area and then turned ON the PDAS system with the console ****, and checked again - the pic is what I found.
I recall seeing a thread or two about these PDAS locks. Can anyone point me to anything helpful? I am afraid to check on cost of one of these.

dfinnegan

I had the transverse diff lock replaced in 2007 at a cost of $375 for the part; from an indy.

DWS964

Does anyone have one of these laying around?

I just checked Pelican price - $655. Ouch.
I will check the prices at the Porsche salvage yards.

I wonder if I should plan on ordering a new hard line for the cylinder as well - it may not come out easily. And then new flex hoses,

I still would like to know if I am at risk of dumping brake fluid into the trans/diff? And, will I need to drain the trans fluid before changing the cylinder? I am not driving it until this is fixed, though.

ian89C4

Darrell,

I had the same problem on mine. I tried replacing the paper seal (part # 92833277600, $1.75 on pelican) and no more leaks. You will have to pull a little hard to get the locking pin that inserts into the trans to come fully out, but I was able to not damage anything in the process. I would say try that prior to buying a brand new dif. lock if all it is is a leak.

Ian

Wachuko

+1 I have it in my to-do list... same issue. The leak is so minimal I have left it for later... but need to get around to fixing it properly.

DWS964

In checking some older posts, I have found:

There is little/no risk of brake fluid getting into the trans (unless, unlikely, the seal in trans/diff is bad, and I will find out if trans fluid comes out when I pull out the diff lock)

Garrett + Kgorman were on a quest a couple years ago to find the appropriate seals to rebuild these rather simple hydraulic devices. I have PM'd both of them to get an update. Keep fingers crossed.

My leak is more than I feel I should "ignore". I need my PDAS for the winter, and I like to keep my brakes, too.

ian89C4

I don't blame you. I did some research and found that they are the same locks as on the 959. They are pretty tough. My seal inside the trans was good and no fluid came out. Just in case though I wouldn't be underneath the assembly when you pull it out and have a catch basin ready, I did, probably why it didn't leak. If I hadn't it probably would have gone everywhere. The locking pin is about 1.5 inches long but is able to move around so you only need to move it about an inch to get the lock out past the studs. My brake fluid line going in to the lock bent a little at the little 'S' curve bend but that was about it. Straightened back out when I bolted it back on.
Good luck!

roblav

Why couldn't someone make these on a CNC machine for about 1/4th the price?

I need a front one (longitudinal), and the rear one (lateral) leaks.

WadeC4

Hi Darrell

Could you use the one off of your "Informant" car if replacing the seal doesn't work?

DWS964

Hi, Wade - Merry Christmas to you and the Missus!

I already considered that option - I hate to start using it as a parts car (but I admit I already have done that for a bit or two...). But if I cannot find a replacement right away, or a way to rebuild, then I will swap out the one from the red C4, and replace it when it goes back on the road (someday...)

Hope to see you on the track in 2010 - Pete and I plan to do Mid-Ohio, Road America, and Watkins Glen.

I received a note from Garrett - he suspended his research into finding suitable replacement seals for these units a couple years ago. Perhaps I will start up where he left off.

roblav

Measure the O-rings in each unit, and you can find them online.