VIKING_MECHANIC
GMT 400 obsessed Swede.
So I am currently experiencing some brake issues that hopefully I can get some feedback. Here's why and how:
About the end of June I went to Joplin to pick up a new project, while towing my newly acquired 18' trailer(which was a bit much for the project - a riding mower, but I sure as hel wasn't loading it in the back of my truck by hand). Anyways, once I was in Jane, I had to come to an abrupt stop because the person in front of me decided to come to a stop for a yellow light, even thought he had time to go through it.
Once I came to a stop from about ~30MPH, I noticed three things:
1 - my rear right brake drum was smokin'
2 - my brake pedal was a bit soft
3 - the parking brake light came on, which after reading some of the threads on here I learned it has two functions: to inform you the parking brake is set; and to inform you of uneven brake pressure in the system.
After I picked up some speed, my brakes cooled off and the pedal got a bit better - not much though. The brake light was still on as I was driving to Joplin - and conveniently went off once I got to my destination. Once I got my new project, the truck and trailer drove just fine back to my house - about 70 miles.
The following day I looked at my drums and noticed that the right side wheel cylinder blew apart - so I replaced both sides and bled the rear brakes.
Nothing changed. Brake pedal is still soft.
Over the next weeks, I bled all four corners and keeping an eye on fluid level. Since this has happened til now - I have bled the brakes about 4 times and the fluid is solid at all corners.
So after reading some threads about brakes I think this is may have happened - As I was coming to a abrupt, quick stop with about 2000 - 2500Lbs pushing against me up a slight incline with a truck who's brake system is working overtime with 400K on the clock. I suspect that the proportioning valve was over pressurized and damaged internally. I even tried that bled valve on the side and it doesn't help.
I suspect it's the proportioning valve/ABS module that has failed and no longer holding pressure. I got another one from pick-it-part but I haven't swapped it out yet.
Also, now my parking brake doesn't work. It will apply, but WAY to soft and won't hold the truck.
Any thoughts?
Trailer info if your curious:
18L'x8.5"W
~2500Lbs
Has a braking axle, but it's not wired into the main harness(it has been abused)
(EDIT)
This is on my 1997 C1500
5.7 with a built 4l60E for towing
About the end of June I went to Joplin to pick up a new project, while towing my newly acquired 18' trailer(which was a bit much for the project - a riding mower, but I sure as hel wasn't loading it in the back of my truck by hand). Anyways, once I was in Jane, I had to come to an abrupt stop because the person in front of me decided to come to a stop for a yellow light, even thought he had time to go through it.
Once I came to a stop from about ~30MPH, I noticed three things:
1 - my rear right brake drum was smokin'
2 - my brake pedal was a bit soft
3 - the parking brake light came on, which after reading some of the threads on here I learned it has two functions: to inform you the parking brake is set; and to inform you of uneven brake pressure in the system.
After I picked up some speed, my brakes cooled off and the pedal got a bit better - not much though. The brake light was still on as I was driving to Joplin - and conveniently went off once I got to my destination. Once I got my new project, the truck and trailer drove just fine back to my house - about 70 miles.
The following day I looked at my drums and noticed that the right side wheel cylinder blew apart - so I replaced both sides and bled the rear brakes.
Nothing changed. Brake pedal is still soft.
Over the next weeks, I bled all four corners and keeping an eye on fluid level. Since this has happened til now - I have bled the brakes about 4 times and the fluid is solid at all corners.
So after reading some threads about brakes I think this is may have happened - As I was coming to a abrupt, quick stop with about 2000 - 2500Lbs pushing against me up a slight incline with a truck who's brake system is working overtime with 400K on the clock. I suspect that the proportioning valve was over pressurized and damaged internally. I even tried that bled valve on the side and it doesn't help.
I suspect it's the proportioning valve/ABS module that has failed and no longer holding pressure. I got another one from pick-it-part but I haven't swapped it out yet.
Also, now my parking brake doesn't work. It will apply, but WAY to soft and won't hold the truck.
Any thoughts?
Trailer info if your curious:
18L'x8.5"W
~2500Lbs
Has a braking axle, but it's not wired into the main harness(it has been abused)
(EDIT)
This is on my 1997 C1500
5.7 with a built 4l60E for towing
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