87 Dakota Brake issues Update and question
#1
03-20-2020, 11:04 AM
Join Date: Mar 2020
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87 Dakota Brake issues Update and question
I posted about a week ago.
So after a lot of trial, error and research I found that if the lines (which i replaced) going to the HSPV were disconnected the valve would have to be bled seperately because air can get trapped in the valve. The valve is the original, I twisted one of the two bleeders off right away, put it into a shop to get them to try and remove the bleeders but they messed up and the HSPV is now useless.
So I read that the valve can be bypassed. Here is my understanding of how to bypass it and what I did. The truck has two lines from the combo valve back to the HSPV, one line comes straight back from the back of the combo valve, the other comes back from the bottom of the valve. Both lines run along side of the chassis to joiners and up to the HSPV. I plugged the line from the back of the combo valve at that joiner and ran a line from the other joiner to the rubber line going into the T on the rear end (basically now a straight shot to the T on the rear end). RE bled the brakes AGAIN and same issue, pedal goes to floor, I know the booster and MC are good. No leaks or low fluid.
My question is did I block the right line, does it matter where i block it, does it matter where the straight line connects to the rear (hose or T on the rear) if there is air in the blocked line would it matter for that line. If anyone has done this with bypassing the HSPV let me know.
The truck will not be used for weight so I'm not concerned about the valve just want brakes lol
Thanks for all the advice
So after a lot of trial, error and research I found that if the lines (which i replaced) going to the HSPV were disconnected the valve would have to be bled seperately because air can get trapped in the valve. The valve is the original, I twisted one of the two bleeders off right away, put it into a shop to get them to try and remove the bleeders but they messed up and the HSPV is now useless.
So I read that the valve can be bypassed. Here is my understanding of how to bypass it and what I did. The truck has two lines from the combo valve back to the HSPV, one line comes straight back from the back of the combo valve, the other comes back from the bottom of the valve. Both lines run along side of the chassis to joiners and up to the HSPV. I plugged the line from the back of the combo valve at that joiner and ran a line from the other joiner to the rubber line going into the T on the rear end (basically now a straight shot to the T on the rear end). RE bled the brakes AGAIN and same issue, pedal goes to floor, I know the booster and MC are good. No leaks or low fluid.
My question is did I block the right line, does it matter where i block it, does it matter where the straight line connects to the rear (hose or T on the rear) if there is air in the blocked line would it matter for that line. If anyone has done this with bypassing the HSPV let me know.
The truck will not be used for weight so I'm not concerned about the valve just want brakes lol
Thanks for all the advice
#2
03-20-2020, 11:32 AM
Champion
My understanding is - you needed to use the line on the back of the proportioning valve; the one that tied to the front is a feed back line, and now ALL your brakes are off one of the two parts of the master cylinder.
You would run straight to the rubber hose. The hose runs down to the axle; on the axle is the T fitting. You don't need any other T fittings in there (where would the other line go?)
If the pedal goes to the floor, but you have good pressure with the motor off, it's the booster. Do remember, they DO have warranties for a reason.
RwP
You would run straight to the rubber hose. The hose runs down to the axle; on the axle is the T fitting. You don't need any other T fittings in there (where would the other line go?)
If the pedal goes to the floor, but you have good pressure with the motor off, it's the booster. Do remember, they DO have warranties for a reason.
RwP
#3
03-20-2020, 12:09 PM
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Im still not 100% sure. I unplugged the vac line to the booster and lost of vacumm, i pulled the chedk valve and it seems to be holding vacum. the booster has a warranty yes, the parts store and the company said they sometimes do get bad or faulty boosters go out. I was hoping not to have to pull it off again, its a pain in the *** to remove and of course there is still no guarantee i wont get another bad one
Im guessing my other question about which line from the combo valve is the right on.
Thanks
Im guessing my other question about which line from the combo valve is the right on.
Thanks
#4
03-20-2020, 12:16 PM
Champion
Dude.
Apply vacuum, goes all the way down.
The counterbalance inside the booster is not working.
Especially if the pedal is hard without vacuum.
Take a look at how vacuum boosters work sometimes. They're not boxes of magic, they're basic pneumatics. Here's one text with pictures: https://www.quora.com/How-does-a-Vac...-brake-booster What it SOUNDS like is that the poppet valve is stuck open.
RwP
Apply vacuum, goes all the way down.
The counterbalance inside the booster is not working.
Especially if the pedal is hard without vacuum.
Take a look at how vacuum boosters work sometimes. They're not boxes of magic, they're basic pneumatics. Here's one text with pictures: https://www.quora.com/How-does-a-Vac...-brake-booster What it SOUNDS like is that the poppet valve is stuck open.
RwP