914 Brakes Work to Good

[Northern Chris]

Took the 914 for a spirited spin into town the other day. Went into a store came back 10 minutes later and had trouble getting the car to move, the brakes were stuck partially on. Petal was really stiff. Got about half a block and then had to park and call a tow truck. After waiting about 45 min for the tow found the brakes had released and drove the car home.

I'm brave so next day drove cautiously with no problems, the following day while driving the brakes slowly came on and had to park after 3 miles, this time all four brakes were tight and petal was solid - brakes weren't to hot as still could touch with fingers. Waited an hour then could drive again, half a mile later brakes tightened up again (much hotter this time could smell), was tired of waiting so bled down one front brake cylinder and was able to move the car again and get it home. I had a new master cylinder installed this summer could that be the culprit?

Any suggestions where to start looking?

[Dave at Pelican Parts]

Brake lines. They can swell internally--your foot on the master cylinder will produce enough pressure to get fluid past the obstruction, but the relatively weak action of the caliper seals pulling back on the caliper pistons won't produce enough pressure to push the fluid back the other way.

That'd be my guess...

--DD

[peter carroll]

Yes, change those rubber brake hoses. Pete

[campbellcj]

A stiff and sticking pedal can also be swelled pedal cluster bushings; which are typically caused by a leaking master cylinder.

If the pedal is really stiff and inconsistent but doesn't feel sticky or notchy than it's probably the lines as mentioned above.

Another possibility is sticking caliper pistons.

Bottom line is that brakes are not something to skimp on; best to inspect and refurb any component that needs it.

[Northern Chris]

Thanks, I'll start with the rubber brake lines and the wheel cylinders, after all is said and done it could be a combination of both as one rear wheel is hard to turn but no brake fluid would bleed off. Looks like the brakes will keep me busy for the winter (I know I'm from Canada and its already snowed so I'll have nothing better to do).

[BigD9146gt]

Chris, start with the lines like Dave said, thats the cheapest. Then if they keep doing it, then the rubber O rings that seal the caliper pistons and surface rust on the pistons are the problem. The O ring pulls the piston back when you let off the brake. Those are not too bad to rebuild, I clean the pistons with a 000 steel wool and WD40. Anything too abrasive will ruin the seal.

Good luck, Don

[Doug M]

REBUILD THE CALIPERS.
I allways split them with no problem. It is a lot easer and the O RINGS have allways worked again. ...........
Doug
and buy ss brake lines

[Northern Chris]

Thanks for the help. Slowly taking everything apart, any tried and tested techniques in getting old brake fittings apart and removing the pins to pull the rear brake shoes? This car had been sitting for 18 years (inside) prior to my restoration and most things are a bit tight. Right now just soaking everying in "liquid wrench" and gently encouraging.

[calbrat]

Same exact storyhappened to me after I my calipers rebuilt (Except the AAA truck showed up in 10 minutes, with FLAT BED!!! Freaking Amazing!!!). Turns out my master cylinder blew with the new found pressure. Damn 30 year old parts. I put a Mercedes master cylinder in, car stops on a dime. Nice upgrade.