Soft brake pedal

homelessduck

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All I can say is I had the same issues as you with the soft pedal and new hoses fixed it, I did have issues with dragging brakes and it fixed that as well.

I'll order some and give it a try. Did you have visible issues with your hoses?

Just a thought, but did you check the booster pushrod to master cylinder gap? I think it's supposed to be just a hair under an inch (0.980-0.995?)
No I haven't.

But have you looked for bulging while someone is stomping the pedal down?

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I didn't noticed anything as I bleed each line but I will toss some new ones on and hope it does the trick.
 

Thewespaul

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Hope that fixes it up for you, brakes are important. And no one like bleeding brakes over and over again
 

homelessduck

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Brake lines came today. Only got one replaced and had to stop for the day. I'll finish it up tomorrow morning.
 

homelessduck

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Zero at the moment lol. I got the two front ones on but the rear is being a pita. Going to drop the spare tire and hopefully have better access. Of course it decided to snow.. so not moving very fast.
 

homelessduck

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I finally got around to installing the rear hose, and I re-bleed everything. No change. Still has a soft pedal that goes basically to the floor before it even thinks about stopping the truck. Is it safe to say the problem is the rabs? Or is there something else I can try?
 

DrCharles

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Without reading the whole thread over again... have you tried disconnecting the hard lines from the master cylinder, plugging the ports and then stepping on it? If the problem is downstream of the master, the pedal will now be firm. If it's still soft, the problem is in the master...
 

homelessduck

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Yes I did. New master cylinder , bench bleed , nice and firm. It is definitely something down stream.
 

Booyah45828

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Didn't read the entire thread, but I had a truck where the front calipers would flex causing a soft pedal issue. Blocking off the ports from the master cylinder narrowed it down to the front. Clamping a vise grip on the hoses (was getting new lines anyways) towards the calipers left nothing but the calipers to have the issue.

Upgraded to a larger bore master and the problem seemed to be remedied. Fluid looked perfect and everything was bled out numerous times. Caliper flex was the only thing I could come up with. An old tech at the dealer clued me on to the larger bore master being the fix. I think there might have been a tsb or something on this as well.
 

homelessduck

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Tried only blocking front or rear at a time?
Time to get some male and female plugs and work down stream.

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Hmm , no I haven't. However I did notice the rear doesn't have nearly as much pressure when I bleed them. Didn't notice before. I'm not sure what that could mean... plugged line maybe? Also now the rear steel line at the master I can't get to seal completely , probably from removing and installing it a million times. So I guess I get to replace that line too. Can't say it didn't need it, the nut was completely rounded off by the po.
 

homelessduck

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Didn't read the entire thread, but I had a truck where the front calipers would flex causing a soft pedal issue. Blocking off the ports from the master cylinder narrowed it down to the front. Clamping a vise grip on the hoses (was getting new lines anyways) towards the calipers left nothing but the calipers to have the issue.

Upgraded to a larger bore master and the problem seemed to be remedied. Fluid looked perfect and everything was bled out numerous times. Caliper flex was the only thing I could come up with. An old tech at the dealer clued me on to the larger bore master being the fix. I think there might have been a tsb or something on this as well.

I'll see if I can narrow it down some more today.
 

homelessduck

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Well , I'm done with this truck for a while. I finally started making progress on the brakes , went to start the truck and it wouldn't start. Checked a few things , still wouldn't start. Hooked up a gauge to the fuel bleeder and it has almost zero pressure. Maaaybe 1psi. It does spit fuel out while cranking with the bleeder needle out , it just doesn't have any pressure. So I guess the lift pump magically went out over night ...
 
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