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View Full Version : 87 MM - am I supposed to not have power brakes?



jprime84
10-13-2014, 12:31 PM
My brakes work fine with no spongy pedal, but if I want to stop I really have to PUSH on that pedal. It feels like I dont have power brakes or something. Is this normal, or has something gone bad?

ragragtimetime
10-13-2014, 01:25 PM
I had that issue on the 1986 4wd & it was the load sensing proportioning valve (the thing with the spring behind the gas tank) the 1983 4wd does NOT have an LSPV & stops far better...hmmmm

royster
10-13-2014, 03:53 PM
Also, be sure to check the vacuum line going into that master-cylinder thing on the firewall: that's the booster. If the vacuum line is clogged or detatched, it would certainly cause that problem.

RRTT's experience reinforces a post I made not long ago: these trucks have designer problems, and new ones crop up all the time! It's great we have a place to pool that information.

jprime84
10-13-2014, 05:47 PM
I had that issue on the 1986 4wd & it was the load sensing proportioning valve (the thing with the spring behind the gas tank) the 1983 4wd does NOT have an LSPV & stops far better...hmmmm


Was that something you could clean, or did it need to get replaced?

ragragtimetime
10-13-2014, 06:31 PM
so...you press on the pedal & it depresses to "normal" level & it just doesn't stop til you reach the next town...11537115381153911540...i had to replace valve & spring. try adjusting first & see if any change occurs....then bleed...also verify lines are not clogged/collapsed anywhere else.

jprime84
10-14-2014, 06:27 AM
I'll take a look at my manual. I really hope nothing needs to get replaced. Where did you find your part of that is what is needed? I am not readily finding anything online.

ragragtimetime
10-14-2014, 11:20 AM
bought mine from dealer....back in 1991...& its is for sale if you need it:)

jprime84
10-14-2014, 11:44 AM
bought mine from dealer....back in 1991...& its is for sale if you need it:)

That is good to hear! Hang onto it and give me time to check mine out :)

ragragtimetime
10-21-2014, 08:03 AM
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