ShopTalk Forums | Aircooled VW Tech & Restoration Help

forst of all, i think my problem is the rear perportioning valve.

i have had this problem of squishy brakes, and needing to pump the petal twice to obtain minimal petal distance. i bought and installed dot approved SS lines, rebuilt all 4 calipers by hand, and installed a new 19mm master cylinder.

i run 320i's in the front and stock rears but i will upgrade the rear calipers to the original front ones soon.

i have gone through 2 whole quarts of brake fluid (brand new too) bleading the brakes and i absolutly cannot get rid of the spongy petal. i think my perportioning valve is at fault and was wondering if it would be OK to throw in a solid "T" instead, or if anyone else has had this problem and knows of a solution.

i blead each caliper about a dozen times between the 2 quarts and the spongy feeling does not go away.

btw i dont know if this is related or not but when i put the braking system back together i could not get the master cylinder to prime, out of frusteration i attached a clear tube to the caliper bleed nipple on the 2 rears and the other end to my intake manifold. i started the car and pumped hard on the petal which started sucking out fluid and bubbles quickly, it made my exhaust smoke really bad and smelled worse but it got my master cylinder primed. theres nothing quite like the smell of burning brake fluid.

IIC, with the BMW front calipers, the "T" is suggested, and may be one of the best reasons for the conversion.
(just to prevent the same headache you're having)

i guess ill go make one then and try it out.

of course ill to extensive testing (skidding tires on wet grass and then tar) to make sure the fronts still lock up before the rears.

How are you bleeding your brakes? I gave up on the 2 person method long ago.

I got a resavour cap form a junkyard and put a tube fitting on it. Then I attached an airline to it WITH A REGULATOR set to about 10psi. I dont know what the limit of the hoses connecting the resavour to the MC is, but 10 to 15 psi is enough to do the job.

So you fill up the resavour, put on the cap, presureize to 10 psi, and go to each corner and vent for a minute. Be carefull not to empty the resavour.

When doing the right rear, I stabed the brake pedal hard and released slow to drive air out of the prop valve. I think that this helped.

When you rebuilt the brakes, did you inadvertantly install the left front caliper on the right side, i.e., are the front bleed valves on the upper part of the calipers or on the lower. If they are on the lower, that's your problem.
Phil

The odd time on other cars, that I can not bleed proper, I cheat and will crack the brake line open a bit and bleed. May not be the reccomended way, but it has saved my bacon on several occasions.

The best $42.00 I ever spent on brake work was a Power Bleeder. It makes bleeding brakes the easiest I've ever experienced and I've never had a more solid brake pedal feel.