Hydroboost problems

[JCasper]

For a while now I have been having some brake issues. I drove a friends dodge and that is when I first noticed the problem. My brakes don't seem to be as strong, they are kind of spongy. I have a feeling that there is something wrong with the hydroboost unit, but I am not for sure that is the problem. I have a few times been sitting at a stop light and just held pressure on the brake pedal and you can hear a hissing sound as the pedal moves to the floor. It sounds like air escaping. After doing that the brake pedal will seem firmer, but will gradually go back to the spongy feel.



Dodge wants a small fortune to put in a new hydroboost unit. Are they very hard to change, my dad can get mine rebuilt through one of his connections for $160.



Any help would be appreciated.



Joe

 

[jelag]

Couple of thoughts here... .



1 - the hydroboost is run with hydralic pressure from your stearing pump... . not vacuum assisted..... when there was a leak on the old style vacuum assisted power brake boosters you'd hear a hiss... .



2 - a bad master cylinder, or problem with the ABS will allow the pedal to drift to the floor... . this is fluid passing the seals in either location... . there is nothing in the hydroboost chamber to allow this to happen...



3 - your statement about spongy pedal leads me to believe that you might have air in the system... . air will cause the pedal to be spongy... ... and soft... . and can be pumped up as you compress the air... . you can test for this with just a good bleeding of the system... . start with the longest line first ... ... ...



Hope this has helped... ...

 

[JCasper]

To bleed this brake system I was told that you need to exercise the ABS motor at the same time. Should I have the dealer or Les Schwaab bleed the brakes or can I have a friend help me do it in the driveway.



Joe

 

[Monstar]

I had noticed my brakes getting spongy, and my dealer told me it was all normal. About 2K miles later the pwr steering pump went out, and I have not brakes and could barely steer going down the highway. Do you notice that your truck does not turn quite so tight anymore? This was the other symptom that I noticed.



Open the Pwr steering reservoir and look for metal flakes. If they are there go to the dealer and make sure the replace the steering box and the pump.