Feudal Serf

Thanks for the great info here.
FS




Just finished the hydraulic bleeding as well. First lift on the new bendpak 4 post. It was a breeze.

Goughary

Did my c4 and a friends c4 today using your DIY Ricardo. Awesome write up.

This time around I used a pdt999...what a huge difference. Highly recommend.

We bled with the motive bleeder wet. And went through 4-5 liters of ate 200. It was more like 4, but then you have extra in the motive at the end. So I need to remember to buy 5 at a time.

TurboScott

I am trying to work up enough confidence to try this on my C4. Thanks for the details as this helps.

Now all I need is a pdt999 and then a lift for my garage! I guess this project can wait a few more months.

Thanks again.

Goughary

You don't need a lift, just four jack stands so you can crawl under and get to the front diff lock. Car has to be level to bleed so stands are perfect.

Also, the pdt999 made life quick and easy, but another rennlister, nick, made the suggestion a while back to replace the bleeder on the diff locks with m6 x 1 speed bleeders, and with those on you simply crack open the bleeder and sit in the car and turn on and off the diff lock switch. Brilliant. No more real need for special tools. But, it's faster with the pdt.
Don't be shy about bleeding. The previous owner to my car never bled the diff locks and they were seized by the time I started sorting it out. There is a lot of fluid in these cars. You have to bleed them once or twice per year and flush all that fluid out. Otherwise you end up with too much water in the fluid. And too much air.

No car ever suffered from fresh fluids.

TurboScott

Thanks and that is good info. I was not aware that this was a once a year mx item. Sounds like it is time for me jump in and give this a shot.

Thanks again.

Feudal Serf

+1 on don't put off the bleeding.
Prev owner planned it but never did.
My car was sent to a porsche service centre for engine out and trans rebuild (and a new transverse diff lock)
Came back to me with the hydraulic pump running very long over 100 seconds to pressurize.
I knew that air was introduced. And the bleed was long overdue.

I used the motive bleeder and bleed all the sites listed above. The "bomb" had the most air and black fluid.
My advice is start up in the frunk. Attach a battery tender, take your time, be gentle with the bleeder valves

Makes sense, as Goughary says to bleed at the longitudinal lock at the nose of trans. Really easy to get that one, but only after making sure the system is flushed at the pump and accumulator first. Speed bleeders are a neat idea. Lift is a luxury, not a necessity.

cheers

cobalt

First of all great write up however for all those reading this there is no need to remove the metal spring clip. It is a common mistake but the clip is designed to stay in place just push up on it from the bottom and it releases the plug. Also I would not plug the vent hose for the electro-hydraulic system. If you loose power assist the system has about 6-8 good presses of the pedal before you loose power assist completely. If this happens all the fluid in the canister is forced back into the reservoir. When this happens the reservoir cannot accept the extra fluid under pressure and forces it out of the vent tube. Without a place to go it will most likely pop the cover or break the reservoir. The last thing you want is the brake fluid to find its way under the pump or the battery.

Love the RSA but the clamping force of the electro-hydraulic system is superior to the vacuum assisted system used on the C2 and RSA especially if you upgrade the brakes.

Pictures previously posted of the clip if you push on the flat length it unlocks the plug.

C4inLA

Curious, could you define "seized", what seized? Did you remove lock, rebuild? How did you unseize?

Goughary

Seized was the lock cylinder became part of the inner wall of the slave.
I don't remember how I got it loose. I seem to remember removing the retainer ring and I operating the lock. Anyway, the inside of the slave was shot. I honed it a bit, rebuilt it with a new seal.

If you don't bleed the c4 often, you will have humidity in the lines . Humidity causes air and corrosion. And with the amount of damage the corrosion does, better to bleed

spartansix

Hmm, looking through my car's service history I don't see a bleed in the past 12-18 months.

5 quarts of ATE 200 should be enough to everything?

Rocket Rob

I normally use 1-2 quarts when I bleed mine. Having 5 qts on hand would be plenty.

Goughary

If it's a c4 and you are doing a full bleed/flush, and you are doing it wet with the motive, you need to have 6 at least on hand. You will likely use five...

spartansix

Six it is.
Let me know if you're going to have a bleed and flush party any time soon - you have a PDT999, no?

Goughary

Where are you?

Goughary

Ah crap...Dave...I forgot spartansix was you.

Come Sunday if you like. I'll be under John's car all day...pm me.