Sometimes while driving my 86 4runner it will seem as if im pressing the brake while driving. It will accelerate really slow and when i let off the gas it slows down very rapidly, when i press the break it is really stiff. It doesnt happen every time, but every so often it does this. any idea on what this could be?

 

intermittent power supply or ground problems causing the engine to 'die' at random times?

 

the engine runs fine, the reasoning behind me thinking its the brakes is because when i use my brakes my 4runner shakes a little. It does the same thing when im not using my brakes, also when my truck is parked and in neutral i cant push it lol

 

Maybe a sticking caliper?

 

well i think its the rear is where the problems at, but would something like that happen randomly?

 

I didn't realize when I posted you'd already narrowed your choice down to the brakes... lol.
now given what I know now, I could imagine the rear brake cylinders hanging up, or even the front calipers hanging on the sliders. It's not a big deal to disassemble the front's and lube the caliper sliders. If the calipers' pistons are sticking it's best to just replace the caliper. If the rears are hanging up, it's most likely the wheel cylinder(s) themselves need replaced which is a fairly simple procedure. I suppose there could be some grease on the linings but I can't imagine that being an intermittent problem.

 

a spring could have broke and is floting inside your rear drum happened in my dadinlaws dodge

 

If the brakes are dragging that bad, the bad unit should smell really hot.

 

Jack up the truck and spin each wheel till you find one (or more) that have excessive drag. Might be incorrectly adjusted rear bracks or something else...
Just go start lookin

 

auto trans ?

torque converter problem

have seen it happen


if a brake is stuck then one will be way hotter than the others, it will be very obvious when you touch all the wheel hubs, one wheel will be very hot

good luck

 

almost sounds like a vacuum issue from the booster to the manifold lines. hmmmmm?????

 

Check the rear brakes, but man that sure does sound like a torque converter problem to me.

 

i took my truck to pep boys to get them inspected, it was doing it on the way there but when the tech took it for a drive it was fine. He inspected the breaks and he said he couldn't find anything wrong. It was working fine until that night it was doing it for about 30 mins, i parked it for about 20 mins and its worked fine since.

oh its a 5 speed

 

Theres the problem you took it to pep boys!

 

Could maybe have somthing to do with the LSPV???

The shacking sounds like warped rotors but not to sure about the surging feeling

 

You could also have a build-up in one of you hydraulic lines which would make it intermittent. Essentially making your hydraulic lines a one way valve. Most places in Cali will wash all of the gunk out of your lines for $20 – 30 and if it hasn’t been done in the last 2 years I would go for it anyways. Just ask them to only use mild pressure so you don’t rupture any worn fittings and create more problems.

 

When it happens are you pulling over and checking the hub temps right away? I know it is intermitant but did you take jays advice and try each tire individually. The clutch isn't slipping right? do the rpms go up but the speed climbs slowly?

Try rolling down a small hill when this is happening and let your steering wheel go. does it pull to one side or the other?

 

Do you have a lift on the rear? Possibly the e-brake cables are getting hung up on top of the spring and/or the main cable back to the relay/lever on the diff is getting stretched and hanging by axle wrap or flex?