keep losing brakes and im suppose to be wheeling in three hours
08-06-2012, 09:07 AM
#31
CF Veteran
This explains it better than I can type it. LOL
http://www.ehow.com/how_7478889_tell...oster-bad.html
I forgot to add. Try bleeding the master cylinder on the vehicle after bleeding the rest of the system.
http://www.ehow.com/how_7478889_tell...oster-bad.html
I forgot to add. Try bleeding the master cylinder on the vehicle after bleeding the rest of the system.
Last edited by EZEARL; 08-06-2012 at 09:10 AM.
08-06-2012, 10:19 AM
#32
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Year: 1989
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thanks man ill try that this thing is making me pull my hair out i will have brakes will i move it around then the pedal drops but it will pump up and hold while im sittin still
08-06-2012, 10:43 AM
#33
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Year: 1999
Model: Cherokee
Engine: 4.0L
The brake pedal dropping means that the brake system is not holding pressure. There are 3 conditions that would cause this:
1) external leak - self explanatory. check all lines and connections for signs of brake fluid leaking out of the system.
2) internal leak (fluid bypass) - usually occurs in the master cylinder. Can be indicated by loss of pressure BUT NO DROP IN FLUID in the master. Since you have already replaced the MC this is unlikely; HOWEVER I have had the experience of having purchased an NIB, SEALED MC turn out to be faulty.
3) Too much "slack" in the system. ie. the suggestion that perhaps you had the wrong hub and therefore the rotor alignment was out. Since the hub re&re was the work you had done immediately before you started having issues I would be inclined to carefully check your work here. If the rotor is misaligned it could be knocking back the pad further than normal creating additional slack that has to be taken up before the brakes engage properly.
You said the brake idiot light comes on. The switch for that is in the reservoir so SOMEWHERE you are losing brake fluid. Check again for leaks.
The only other thing I can think of would be that the reservoir is not completely full. There are two chambers in the reservoir: one for the front brake circuit and one for the rear brake circuit. As a fail-safe, the two chambers do NOT feed each other. This is so that in the event you lose fluid to one circuit, the other one still has a supply of fluid so that you don't lose the brakes entirely.
If you look down into the reservoir though the filler you should see a "wall" separating the two chambers. to fill the rear you actually need to to fill the reservoir to almost overflowing so that the rear chamber fills. It's very common for people to improperly fill the rear chamber when bleeding the rear brakes or when replacing the MC.
The brake booster is probably NOT the culprit because if it had failed the amount of pedal pressure required to apply the brakes and stop would be significantly more than normal and the pedal would not drop to the floor.
1) external leak - self explanatory. check all lines and connections for signs of brake fluid leaking out of the system.
2) internal leak (fluid bypass) - usually occurs in the master cylinder. Can be indicated by loss of pressure BUT NO DROP IN FLUID in the master. Since you have already replaced the MC this is unlikely; HOWEVER I have had the experience of having purchased an NIB, SEALED MC turn out to be faulty.
3) Too much "slack" in the system. ie. the suggestion that perhaps you had the wrong hub and therefore the rotor alignment was out. Since the hub re&re was the work you had done immediately before you started having issues I would be inclined to carefully check your work here. If the rotor is misaligned it could be knocking back the pad further than normal creating additional slack that has to be taken up before the brakes engage properly.
You said the brake idiot light comes on. The switch for that is in the reservoir so SOMEWHERE you are losing brake fluid. Check again for leaks.
The only other thing I can think of would be that the reservoir is not completely full. There are two chambers in the reservoir: one for the front brake circuit and one for the rear brake circuit. As a fail-safe, the two chambers do NOT feed each other. This is so that in the event you lose fluid to one circuit, the other one still has a supply of fluid so that you don't lose the brakes entirely.
If you look down into the reservoir though the filler you should see a "wall" separating the two chambers. to fill the rear you actually need to to fill the reservoir to almost overflowing so that the rear chamber fills. It's very common for people to improperly fill the rear chamber when bleeding the rear brakes or when replacing the MC.
The brake booster is probably NOT the culprit because if it had failed the amount of pedal pressure required to apply the brakes and stop would be significantly more than normal and the pedal would not drop to the floor.
08-06-2012, 10:48 AM
#34
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Year: 1999
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If the system holds pressure you don't have a leak so you can rule that out. But if you have to pump up the brake after driving then somehow slack is getting introduced into the system when you're driving. chances are there's knock-back occurring. Check the rotor alignment and brake assembly very carefully. I'd suggest pulling off the other tire and comparing the two.
08-10-2012, 02:56 AM
#38
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Year: 1990
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Congratulations on the marriage! Sorry to ask this on your thread, but i've searched and searched to no avail...so you are supposed to depressurize the accumulatora in a bendix 9 prior to opening any lines. It follows logically that this is just to avoid 2000psiusing of brake fluid to the face, but can opening lines without depressuring the accumulators cause any damage to the system components? Because i did (didnt read up before doing brakes). No overwhelming spray to the dome peice, but now the motor purrs and ive had a loss of breaks recently. Thanks in advance for any help, and i hope you get yours digured out as well JDgreen.
08-10-2012, 06:33 AM
#39
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Year: 1989
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im not to sure about the bendix system mine doesnt have abs but if u look back on this thread there a link to a hole write up on it
