icanfixall
Official GMM hand model
#@&%~Brakes!!!!!!!
- Thread starter poolguy
- Start date
poolguy
Slippery when wet
Thanks, ebrakes are working fine @ 1/2 pedaland will hold the truck still.
The rear brakes are adjusted. Tha RABS valve has been bypassed.
Thanks,
Chuck
The rear brakes are adjusted. Tha RABS valve has been bypassed.
Thanks,
Chuck
ramon f350
Registered User
but do you still have the sinking pedal? this has been an issue with my truck and all I get from international and ford techs are that these trucks just do that when they get some miles on them
Ramon
Ramon
poolguy
Slippery when wet
Ramon,
Yes the pedal still sinks. Not to the floor, but way past where the point that stops the truck. I don't know what to do. I don't know who else to ask. I'm very concerned about a possible brake failure under a load. Almost everything is new, and it's still doing what made me want to fix it in the begining.
Yes the pedal still sinks. Not to the floor, but way past where the point that stops the truck. I don't know what to do. I don't know who else to ask. I'm very concerned about a possible brake failure under a load. Almost everything is new, and it's still doing what made me want to fix it in the begining.
poolguy
Slippery when wet
Point taken. Didn't mean to annoy.
Compu Doc
Full Access Member
The test the master cylinder the way the article indicates that I provided a link for. You can narrow down your problem that way. let us know what the brake pedal is like then. By the way just a little FYI. Do not drive the truck while testing the master cylinder. Not saying you would do that but I don't want anyone knocking at my door from my advice given here.
Jeff Dodson
Full Access Member
Well I have done ALL the above, replaced pads, replace booster, replace RABS valve, adjusted rear brakes etc... dadadad... I had a friend of mine, VERY KNOWLEDGABLE, I might add. He told me there was service bullitin from FORD stating that when the front calipers ( BTW, I replaced those as well) are replaced, rebuilt whatever, the original master cylinder does noes pump enough fluid to aal four brakes, therefore causes the mastercylinder to fade down. I fought with this for a year. Finally, I did what my friend said and ALSO what the service bullitin said to do. Install a mastercylinder from an F450. I got one from AUTOZONE for a 96, I believe they are the same for several years. Now if you dont buy the booster also ( as recommended ) then you will have to elongate the mount holes on the mastercylinder to fit it your booster, that will be the only modification need, everything else ghooks up the same.
Now when I did this, someone here told me that was not the right way to fix it, they said, I did not fix the problem, I eliminated it. OK its fixed. Then someone found the service bullitin and posted and it said the same thing.
I'm sure if you do a search you can find it, but its been awhile, 1 year I think, and the brakes are still working great. I did not change the booster, I wish I would have just for piece of mind, but as I said they are fine now and dont fade down. Good Luck with it and let me know if you have any further questions
Now when I did this, someone here told me that was not the right way to fix it, they said, I did not fix the problem, I eliminated it. OK its fixed. Then someone found the service bullitin and posted and it said the same thing.
I'm sure if you do a search you can find it, but its been awhile, 1 year I think, and the brakes are still working great. I did not change the booster, I wish I would have just for piece of mind, but as I said they are fine now and dont fade down. Good Luck with it and let me know if you have any further questions
Mont91
Full Access Member
Hi Jeff, you are talking about me.
Through you we found out that calipers are bored out when being rebuilt(apparently not all) thus screwing up the volume balance in the brake system. This creates an imbalance in the master cylinder and exceeds its ability to compensate. Read that minimal sizing by the engineer.
The larger master cylinder moves more volume thus restoring proper function.
When you replace a part with different specs that solves a problem and you do not know why, you have "covered up" the problem. The problem is fixed yes, but the reason is unknown and may return without warning.
In this case a part that, unknown to us, had non original specs(caliper)and caused the malfunction of an original spec part(master cylinder). This was corrected by adding a second non original spec part(MC) to eliminate the problem caused by the first non original spec part.
Warning,,,,, if you replace your calipers and have the sinking pedal after properly checking the other components the master cylinder may be the problem.
Does anybody know if the caliper specs can be checked at purchase and what the original specs are?
Through you we found out that calipers are bored out when being rebuilt(apparently not all) thus screwing up the volume balance in the brake system. This creates an imbalance in the master cylinder and exceeds its ability to compensate. Read that minimal sizing by the engineer.
The larger master cylinder moves more volume thus restoring proper function.
When you replace a part with different specs that solves a problem and you do not know why, you have "covered up" the problem. The problem is fixed yes, but the reason is unknown and may return without warning.
In this case a part that, unknown to us, had non original specs(caliper)and caused the malfunction of an original spec part(master cylinder). This was corrected by adding a second non original spec part(MC) to eliminate the problem caused by the first non original spec part.
Warning,,,,, if you replace your calipers and have the sinking pedal after properly checking the other components the master cylinder may be the problem.
Does anybody know if the caliper specs can be checked at purchase and what the original specs are?
