Soft brake pedal
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Amateur
Joined: Oct 2023
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Since you replaced all the calipers, know that they will mechanically fit on the wrong side just fine. But the truck will never bled all the air out, because when the wrong side it installed - the bleeder is not at the top of the caliper. Double check where your bleeders are, they have to be at the top.
This actually happens often, I've seen many threads where the OP made that mistake.
This actually happens often, I've seen many threads where the OP made that mistake.
All calipers are installed correctly with the bleeders in the top position. I have (4) new NTK O2 Sensors to put in her tomorrow. Need the truck running strong for some more deliveries. On the last delivery she stalled on me while in heavy traffic.
original O2 sensors were still in the exhaust. Threw a code and died. Did restart no problem.
I have not had time to get back into the brakes.
it's irksome to touch them again because they work fine, but something is not quite right.
Will report back.
Professional
Joined: Jun 2017
Posts: 180
Likes: 1
I appreciate the advice.
All calipers are installed correctly with the bleeders in the top position. I have (4) new NTK O2 Sensors to put in her tomorrow. Need the truck running strong for some more deliveries. On the last delivery she stalled on me while in heavy traffic.
original O2 sensors were still in the exhaust. Threw a code and died. Did restart no problem.
I have not had time to get back into the brakes.
it's irksome to touch them again because they work fine, but something is not quite right.
Will report back.
All calipers are installed correctly with the bleeders in the top position. I have (4) new NTK O2 Sensors to put in her tomorrow. Need the truck running strong for some more deliveries. On the last delivery she stalled on me while in heavy traffic.
original O2 sensors were still in the exhaust. Threw a code and died. Did restart no problem.
I have not had time to get back into the brakes.
it's irksome to touch them again because they work fine, but something is not quite right.
Will report back.
Rookie
Joined: Nov 2015
Posts: 85
Likes: 2
From: CO
Hydraulic control unit
I had a very similar problem a couple years back. It turned out to be the Hydraulic control unit. Here's the old thread:
https://dodgeforum.com/forum/3rd-gen...ake-pedal.html
https://dodgeforum.com/forum/3rd-gen...ake-pedal.html
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Amateur
Joined: Oct 2023
Posts: 25
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Update.
I bled out the Replacement Master Cylinder with the custom lines in an endless loop on the truck. No air.
Hooked the MC back up.
I then used the old lines that I cut into nipples and drew a vacuum on the nipples. Did that on all three lines. Still no joy. Hard pedal with engine off and almost to the floor with engine on.
Bench bled the original TRW Master Cylinder and reinstalled it. Ran the ABS bleed with scanner. Did all 4 corners. No joy.
Exact same problem still exists after replacing every brake component on the system.
If it is the Kelsey Hayes valve body:
It does not seem you can get those anymore.
To me, it's the only thing that could be giving this soft brake feel. And mind you, I have a numbers matching junkyard replacement in the truck now. Same problem as the the OE unit on the bench.
To say again:
The truck stops fine. No pull when stopping.
no leaks anywhere. Brake fluid stays at MAX level.
ABS works as it should. No wheel lock up under ABS with good pulsing and perfect control.
Just a soft pedal that does not go to floor, but close. You can still slide your left foot under the brake pedal when fully depressed.
Something is giving in that Kelsey Hayes valve body causing the mush. Its not air. I have bled the system 1M times! No bubbles. Rock hard pedal with engine off. Start her up and the pedal travels too much.
Other than that bad pedal feel, the truck runs and stops fine.
Any sage ideas???
Thanks!
I bled out the Replacement Master Cylinder with the custom lines in an endless loop on the truck. No air.
Hooked the MC back up.
I then used the old lines that I cut into nipples and drew a vacuum on the nipples. Did that on all three lines. Still no joy. Hard pedal with engine off and almost to the floor with engine on.
Bench bled the original TRW Master Cylinder and reinstalled it. Ran the ABS bleed with scanner. Did all 4 corners. No joy.
Exact same problem still exists after replacing every brake component on the system.
If it is the Kelsey Hayes valve body:
It does not seem you can get those anymore.
To me, it's the only thing that could be giving this soft brake feel. And mind you, I have a numbers matching junkyard replacement in the truck now. Same problem as the the OE unit on the bench.
To say again:
The truck stops fine. No pull when stopping.
no leaks anywhere. Brake fluid stays at MAX level.
ABS works as it should. No wheel lock up under ABS with good pulsing and perfect control.
Just a soft pedal that does not go to floor, but close. You can still slide your left foot under the brake pedal when fully depressed.
Something is giving in that Kelsey Hayes valve body causing the mush. Its not air. I have bled the system 1M times! No bubbles. Rock hard pedal with engine off. Start her up and the pedal travels too much.
Other than that bad pedal feel, the truck runs and stops fine.
Any sage ideas???
Thanks!
Last edited by 2005RAMman99; May 4, 2024 at 04:38 PM.
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Amateur
Joined: Oct 2023
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Well, no joy still. Basically, poured another full day into this problem. Just as an FYI, I am not a rookie on brake work/mechanical work. But this truck has got me flat out stumped!
It has to be the Kelsey Hayes ABS valve body.
And my luck, the replacement I found has got the same problem. Its the only thing it could be.
There are no codes, no ABS/Brake lights on dash.
scanner passes all systems. Using Autel MX808 that has enough function to work well with this model RAM.
If these Kelsey Hayes hydraulic units were available or someone had a service to repair them, well, I would not be here right now.
Not the module, mind you. No problems there.
I guess my only option is to get another used complete ABS unit and pray for the best. That's about a $150 gamble.
There is not anything more to be done.
Its either live with it or roll the dice again.
I suppose I could return this next one if no joy on the result.
2005 Dodge Ram 2500 SLT HD
5.7 HEMI
4X4
Quad Cab
8' Box
4 Wheel Anti Lock Brakes.
4 Wheel Disk Brakes
All new SST brake lines. New brake hoses. New brake calipers. New pads. New rotors. New Master Cylinder. Swapped out Booster, no change.
swapped out Kelsey Hayes complete ABS unit, no change. Reinstalled original TRW Master Cylinder, no change. Bled system to the point of madness. 7-10 quarts through the system. No air, no bubbles.
Sucked with large vacuum canister at all corners. Used pump and hold method with helper. ABS bleed many times with scanner. Bled again and again and again and again. Rock hard brake pedal with engine off. 1 inch of travel. Start engine, Soft brake pedal almost to floor.
Anyone have a source for one of these Kelsey Hayes NEW Units?
Thanks.
It has to be the Kelsey Hayes ABS valve body.
And my luck, the replacement I found has got the same problem. Its the only thing it could be.
There are no codes, no ABS/Brake lights on dash.
scanner passes all systems. Using Autel MX808 that has enough function to work well with this model RAM.
If these Kelsey Hayes hydraulic units were available or someone had a service to repair them, well, I would not be here right now.
Not the module, mind you. No problems there.
I guess my only option is to get another used complete ABS unit and pray for the best. That's about a $150 gamble.
There is not anything more to be done.
Its either live with it or roll the dice again.
I suppose I could return this next one if no joy on the result.
2005 Dodge Ram 2500 SLT HD
5.7 HEMI
4X4
Quad Cab
8' Box
4 Wheel Anti Lock Brakes.
4 Wheel Disk Brakes
All new SST brake lines. New brake hoses. New brake calipers. New pads. New rotors. New Master Cylinder. Swapped out Booster, no change.
swapped out Kelsey Hayes complete ABS unit, no change. Reinstalled original TRW Master Cylinder, no change. Bled system to the point of madness. 7-10 quarts through the system. No air, no bubbles.
Sucked with large vacuum canister at all corners. Used pump and hold method with helper. ABS bleed many times with scanner. Bled again and again and again and again. Rock hard brake pedal with engine off. 1 inch of travel. Start engine, Soft brake pedal almost to floor.
Anyone have a source for one of these Kelsey Hayes NEW Units?
Thanks.
Thread Starter
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Amateur
Joined: Oct 2023
Posts: 25
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Theoretically, this is the correct unit for your truck. I can't figger out if it is the whole thing, or just the electronics part of it though.....
I will call them Monday to see if that is a complete hydraulic unit or just the module Etc.
Really appreciate the lead!
I shall return! 👍