LUVTruck.com

i have a very soft pedal on my 79 luv if you just barlry push it and they lock up and sometimes the pedal sticks for a second pads look good and i bleed them could it be the booster or master cylinder?

Is it all four tires locking up, just one, just the fronts, rears? There are a lot of things that can cause brakes to lock up but it would really help to narrow it down if it happens to be a particular wheel or end of the truck having the problem. You could be looking at drums out of round, bad master cylinder, sticky calipers, all sort of stuff. I think we can get you some better help with more info on the symptoms of the problem.

I had sticking calipers on my 79 4x4 when I first got it back on the road, but only one side. It would heat that side up and then pull hard to the other side when you hit the brake pedal. It did change the feel of the pedal as well, but I don't recall it sticking. I would think that would be a sign of problems in the master cylinder or the booster like you mentioned, but I've never had that specific symptom on any of my LUVs before.

A couple more questions that might help sort more of this out: Has this truck been working right and just came up with this problem all of the sudden or was something done to it just prior to this cropping up? Is this a truck that had been sitting quite a while and has recently gotten back on the road?

I'll have a look at my factory 79 shop manual for brake symptoms and see if it comes up with anything. I'm sure someone of us here will be able to get an answer for ya.

I dont think that they are locking up so much now it is just the pedal is verrrry touchy i can apply full brakes with just the weight of my foot. I tried to bleed them again but still no luck. I just bought the truck and i was told it had been sitting for 2 years. The pedal is still sticking though, sometimes it does not come back until I start moving. But bad brakes or not i still like my new truck!!!!

Welcome to the site, and I am glad to hear that you like your truck. Be patient grass hopper, and I know some one here will lead you on your way to fixing your brakes!

you need to talk to me because if you need master cyl or brake booster i have them both here an will be happy to bring either or tomm nite along w your trans when i drop it off

Im thinking that your year truck came with a proportioning valve. It's were the brake lines go to after they leave the master cylinder. If so, i'd check that out after making very sure that the calipers are not sticking or binding. If the proportioning valve is screwed up, it wont apply pressure correctly between the front and rear brakes. All of your pedal pressure could be going to the front brakes. As for the sticking brake pedal, make sure that the pedal pivot is ok. It might need to be lubed. I highly doubt that the master cylinder is bad if you have such braking force to lock the wheels.
My truck sat for years. While fixing it up i replaced the master cyl, retro- fitted disk brakes up front and the 9" axle had new cyl's, shoes and drums. The only thing that was original was the metal brake lines from the master cyl to the wheels. I would strongly suggest that you go thru the entire braking system of the truck. Not replace everything mind you, just go thru it all and flush the lines and clean the calipers so they slide smoothly, turn the drums, rebuild the wheel cylinders if need be, clean and lightly lube the adjusters. I dont know if proportioning valves can be rebuilt or not, or if there's a good way to test it. Hopefully someone can shed some light on this.

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Previous setup: 4.1 Buick V-6/TH 350
Current setup: 400 Small Block Chevy V-8/TH 350
9" ford rear end/short bed/blue
What do Water, Electricity and Humans have in common... They all travel the path of least resistance.

I would highly recommend you rebuild the brake cylinders. The kits dont cost much. My brakes were acting funny like what you described, and my right rear tire always wanted to lock up. Problem solved after I rebuilt both rear cylinders. During the rebuild I found a large amount of rust and crud, and one of the springs inside the cylinder was in pieces.

Chase, install the master cylinder I brought you and then let me know whats happening afterwards. i had a 79 2wd that was doing similiar things a few years ago, and all i did was install new master cylinder and took back drums off and sprayed break parts-cleaner in there on everything and then a lil WD-40 and it fixed my prob. keep me informed, like i said bud ill help as much as i know how.
By the way guys that is a real nice lookin lil truck he has there, I was quite impressed w the appearance.