Hello Everyone,

 

I'm posting this for a relative who has an 87' DL Wagon (Carb'd, and runs like a champ). He found this forum and wanted to see if anyone here might know how to help with this problem.

 

The wagon's brake lines rotted and were repaired. The system has been completely bled and when the car is off there is plenty of pedal pressure. However when you start the car, the pedal pressure goes away and is very faint, the drivers side front and passenger side rear brakes seem to not work. The car isn't leaking any fluid. We are stumped.

 

Any ideas on how to troubleshoot this problem? Anyone else hit this issue before? Vacuum booster troubleshooting perhaps?

 

Thanks for your help

You may need to bleed the master cylinder first before bleeding the lines. The systems uses two circuits controlling diagonal wheels independantly, in the case of a leak (or air) in one side of the system the master cylinder has a failsafe that will allow the other circuit to still operate - but with more pedal travel. Bleed the master cylinder first, and then the wheels - make sure you have the e-brake off when you bleed too.

 

GD

Definitely look at the master cylinder. If you haven't done so, "bench bleed" it (can be done on the car, basically loop little hoses from the outputs back to the fluid tank, get all the air out). If this doesn't help, you may have a bad master cylinder. If it was totally empty, the insides could have built up some rust, and chewed up the seals when it was used again. Or, you could have a bad vacuum booster.

 

-=Russ=-

try bleeding the drivers front and passenger rear with the engine running and see what you get.

 

but you need to remember that the brake pedal will feel differently when the engine is running versus when the engine is off and you have no vacuum.

a bad booster is detected by hearing a vacuum leak under the dash particularly when you are apply the brakes while the engine is running and also when you apply the brakes while you are driving your brake pedal will be high and very hard to push with very little braking ability.

 

one other thing to is make sure your rear brakes are adjusted up properly, this will effect your brake pedal feel too.

http://www.ultimatesubaru.org/forum/showthread.php?t=39459&highlight=brake+pedal+goes+to+the+floor

Thank you for all the good info.

 

We'll give it another crack with all this information and let you know how it progresses