91 pickup brake issue
#1
Registered User
Thread Starter
Join Date: Oct 2015
Location: West Virginia
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
91 pickup brake issue
I’m having a strange brake issue that I can’t seem to find any information on. I had to replace the 2 lines that run from the front to the back. Ever since I’ve replaced the lines I can’t get the brakes to work. I’ve bled the brakes over and over again. I’ve replaced the master cylinder. I get the same result over and over. I get pressure while I’m bleeding, but when I start the truck all pressure goes away. The pedal goes straight to the floor. I don’t see any air bubbles coming out when I’m bleeding. Can anyone help?
#2
Registered User
Are you sure they are not swapped at the back at the Load Sense Valve?
Bleeding the whole thing starting at IIRC one back wheel and ending at the front??? is a unique process.
Bleeding the whole thing starting at IIRC one back wheel and ending at the front??? is a unique process.
#3
Registered User
You didn't mention how you bled your brakes or IF you bled the load sensing proportioning valve. It sounds to me like that may be your issue or like ghill said, maybe you inadvertently swapped the lines.
#4
Registered User
Thread Starter
Join Date: Oct 2015
Location: West Virginia
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
So to be honest this is my first time messing with a brake system, and I’m not sure what or where the LSPV is. Would this be it, above the right rear wheel?
#5
Registered User
Thread Starter
Join Date: Oct 2015
Location: West Virginia
Posts: 14
Likes: 0
Received 0 Likes
on
0 Posts
I don’t think that I accidentally swapped the lines. I flagged them so I wouldn’t. if they were swapped though would that give me this issue? Maybe I did accidentally swap them
#6
Registered User
There is a bleeder screw on the valve and you likely have air in it. I don't remember the proper method of bleeding this so check the service manual or maybe someone else will chime in with the steps.
Also, if the arm gets bent it can mess with your rear brake operation.
Since your pedal goes to the floor it's likely air in the lines.
#7
Also, as a general rule, bleed from farthest wheel from master cylinder to closest wheel. I'm guessing the order here should be rear passenger, lspv, rear driver, front passenger, front driver. Someone can correct me if the lspv should be bled at a different stage.
Trending Topics
#8
Registered User
Good luck!
Pat☺
The following users liked this post:
2ToyGuy (05-04-2020)
Thread
Thread Starter
Forum
Replies
Last Post