Brake problems, can anyone help me?!?
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Brake problems, can anyone help me?!?
I have a 1987 ford f350 6.9L Diesel and I have very poor brakes. I put a new master in, bench bled it and then bled all the other brakes starting from the furthest point. I also adjusted the rear drums. All the steel lines are in good shape and don't need replacing. A friend of mine said it sounds like it could be the brake booster and another said that maybe the vacuum pump isn't creating enough vacuum. Can you tell me how much vacuum it is supposed to be putting out so I can test it and if you think it can be the brake booster. I also read on a forum that there is a rab valve on the driver side and that this needs to be bleed as well. What is a rab valve?
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From: Princeton MN
Rab is rear anti-lock barkes. my 84 aint got that. But vac pump shoulsd put at least 22in.hg some say 22lbs but vac is in inches of mercury. Hold the brake down with the truck off, start it if it pulls down the booster should be fine. with vac check that little check valve on the booster (with vac on the system and truck off pull the vac line on the booster if you hear a woosh its working) Some guys have exact specs on the pumps but try these things til they get here
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Rab is rear anti-lock barkes. my 84 aint got that. But vac pump shoulsd put at least 22in.hg some say 22lbs but vac is in inches of mercury. Hold the brake down with the truck off, start it if it pulls down the booster should be fine. with vac check that little check valve on the booster (with vac on the system and truck off pull the vac line on the booster if you hear a woosh its working) Some guys have exact specs on the pumps but try these things til they get here
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Alright sounds good. I just don't know what the "juice tin on the pax fender" is...haha, sorry.
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Cargo Master
Joined: Feb 2010
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From: NY
The brakes should work well regardless of the tin can being rusted out or not, mine was rusted out for a while and it braked the same.
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i have a list off of a alldata thats gives u steps on how to check the vac. pump if u follow this it will lead u down a check list to singal out the problum, it will tell u if its the brakes of the pump
i have a list off of a alldata thats gives u steps on how to check the vac. pump if u follow this it will lead u down a check list to singal out the problum, it will tell u if its the brakes of the pump
Logistics Pro
Joined: Sep 2007
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From: Western Mass
Did you bleed the RABS unit? its on the drivers side frame below the cab, near the engine. That should probably be your first step.
Also, define "very poor brakes"
Is it poor as in hard pedal? Could be bad booster or vac pump.
Mushy pedal could be air in system, leak in system, bad fluid, bad brake hoses.
The RABS system in these trucks is pretty crappy in many peoples opinions. Its not really needed, and your truck should stop fine without it if everything else is working right.
Also, define "very poor brakes"
Is it poor as in hard pedal? Could be bad booster or vac pump.
Mushy pedal could be air in system, leak in system, bad fluid, bad brake hoses.
The RABS system in these trucks is pretty crappy in many peoples opinions. Its not really needed, and your truck should stop fine without it if everything else is working right.
i ain't rite
Joined: Mar 2005
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From: Marlboro Mental Hospital.
87 does not have a VSS. 87 has a speedometer cable on the tailshaft of the trans on a 2 wheel ,and the tailshaft of the transfercase on a 4 wheel drive.
Post Fiend
Joined: Nov 2005
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From: Charles Town, W bygod Va
If it has antilock it has a speed sensor.