Brake pedal slow to return

Clubbs

Well-Known Member
Joined
Jun 15, 2008
Location
Blounts Creek
My 05 Cummins brake pedal comes back slowly. Not a big deal unless pulling a trailer with electric brakes. I replaced the hydoboost and no change. Flushed the power steering fluid and the brake fluid - no change. While doing the brake fluid the front left seemed restricted so replaced that line - no change. Master cylinder had blow by anyway so replaced that - no change to the slow pedal return. Put new front pads on cuz they needed it - no change to the slow pedal return. Pretty sure the booster is responsible for how quickly the pedal returns, and the one I bought was a rebuild from advance. Anyone have any other ideas before I put another booster in it?
 
Calipers stuck? Caliper slide bolts maybe? It appears that nobody makes a NEW hydroboost for them anymore, so it kinda looks like you're stuck with remans, unfortunately.
 
Sounds like you've got a bad booster. Slow brake pedal return would be due to lack of pressure in the system with the pedal applied.
 
I'd be tempted to cruise the face list and craig's space to find a wrecked truck to snag one off of maybe. I'd guess there could be a chance that the power steering pump is weak too, right?
 
Maybe, but brakes and steering seem fine, it's just the return is slow. Pretty much returns the same as the master cylinder piston retracts. There is no assisted return from the booster. Replacing the booster the first time didn't change a thing... And they're not cheap, but neither is a power steering pump.
 
VortecJeep said:
School me on the relationship between the steering pump and brakes please.
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Hydro boost. Hydraulic brake boost as opposed to more common vacuum boost
 
Straight from my old textbook, probably the booster.

Also make sure the pedal moves free. If its pivot is rusty or dried out it'll make the pedal slow too.
 

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VortecJeep said:
School me on the relationship between the steering pump and brakes please.
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I have better pics somewhere, but here is one. The Hydro unit, is behind the MC, where the vacuum booster usually sits. Boost is by hydraulic pressure, from the power steering pump. That's the extra PS lines you see, that tie into the PS.
 

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Pump -> booster -> steering

What pressure the booster does not need is fed to the steering. If you get on the brakes hard enough, you'll lose steering (also can be a sign the pump is failing). Both have seperate fluid returns to the reservoir.
 
Chris_Keziah said:
Sounds like you've got a bad booster
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This. I've never had this problem with a hydroboost truck, but I've had vac boosters that got replaced every winter because they were cheap ass A-1 Cardone rebuilds and only lasted about a year before the pedal wouldn't come back up on its own.
 
Replaced the booster with another one from advance. Turns out it's a lifetime warranty so its "free". Regardless this one is worse than the first one... Which I could buy a new one.
 
Maybe, just figured I would try another one since it's a life time replacement thing. But may have to go to the stealership next
a_kelley said:
Their power steering pumps suck too. Can't get one at the dealer?
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Nope. Trans lost a gear in Florida towing a borrowed gooseneck. Spent $5k on a trans rebuild down there and he must have shorted the harness in the process. Drovr 100 miles and it would throw a code and go in limp mode. Tried three times over 3 weeks, 5 one way plane tickets, and a huge hassle. My buddy needed his trailer back and the trans shop couldnt figure it out. He gave me $2,500 back , transferred the trans warranty to the dealer and I had to trade her in on an 18 mega. Replaced the hydro boost thing before I traded it for the third time and it was still bad. Someone else has it now. Hopefully they got it straight. I disclosed everything to the dealer. Someone got a nice rig with a brand new built trans. If I just could have got it home I'd a figured it out and still be driving the paid off truck. Love the 18 but got a few more payments to go
 
Nope. Trans lost a gear in Florida towing a borrowed gooseneck. Spent $5k on a trans rebuild down there and he must have shorted the harness in the process. Drove 100 miles and it would throw a code and go in limp mode. Tried three times over 3 weeks, 5 one way plane tickets, and a huge hassle. My buddy needed his trailer back and the trans shop couldnt figure it out. He gave me $2,500 back , transferred the trans warranty to the dealer and I had to trade her in on an 18 mega. Replaced the hydro boost thing before I traded it for the third time and it was still bad. Someone else has it now. Hopefully they got it straight. I disclosed everything to the dealer. Someone got a nice rig with a brand new built trans. If I just could have got it home I'd a figured it out and still be driving the paid off truck. Love the 18 but got a few more payments to go
 
If the pedal is not returning then fluid is not getting back to the master from the calipers to allow the piston to retract fast enough. To me this is a stuck caliper or an internally collapsed line. I would change the all the other soft lines on the truck since they are nearly 20 years old anyway. My bet is on the soft line going from the frame to the rear axle since that controls a large volume of fluid movement.
 
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