Hello all,
I'm new to the site, and new to having a Toyota pickup as well.
I recently bought a 1990 Toyota 4x4 ext cab, it's got the 3.0 EFI engine with a 5 speed manual transmission, I don't know the technical terms of either or how to tell, I was told that it's an SR5, not sure of that either. What I am sure of, is I've always wanted one since the Back to the Future movies came out, I fell in love with these trucks.
The truck looks and runs great even for having 277000+ miles on the odometer
As for any used vehicle I've bought over the years I like to give them full tune ups, just so I know for sure when it was last done, this Toyota is no different, it's getting the works.
I was turned on to this site for any questions I may need help on while I embark on this journey to make this Toyota my dream truck, mind you it won't be a street princess no sir, this beauty will see lots and lots of mud.
With that said, here is why I started this thread,
I have been having lots of issues with the front brakes locking up, like others here I've read about, but mine seems to be slightly different, while I have good pedal, I've flushed out all the lines, replaced the hoses in the front, got brand new calipers, a new master cylinder, I've bled everything with a one man bleeder, then again with a buddy to be sure, I've checked the rear brakes and the emergency brake, everything is as it should be, or so I thought, even after all of that, today coming home from work, it's started doing it again, I've checked the vacuum line to the booster, it looks good as well,
It's acting like a check valve is letting fluid to the front calipers, but not from, now after a few minutes of sitting it releases and the front tires will roll fine, if a go somewhere it builds up pressure and then the pedal becomes hard, and a flee fart could put you through the windshield.

Update::: the guy I bought the truck from, just called and said he had removed the metal bracket under the dash that the pedals connect to to have it welded at the clutch pedal mounting area, he had a new clutch put in thinking it had went out, come to find out it was the broken bracket, so could it be it's out of adjustment there that's causing my issues,
I'd prefer to do all the work on this truck if possible, what better way to know it

Anyway thanks for any input.
James


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Sounds like the brake master cylinder piston might not be coming back to its completely released position.

The brake actuation rod behind the master cylinder (inside the brake booster) must be short enough to have a little play so that the master cyl piston can come completely back to rest

Only when that piston is completely back are the ports clear that release fluid back into the master from the brake lines.

The same issue could occur at the pedal where its rod enters the brake booster. The rod might be long there

 

Hmmm interesting, I wonder if when removing the booster and pedals and such, if maybe they forgot something or did something wrong while under there, or simply didn't set something in right, I guess I'll need to invest in a chiton manual, so I can do it right.
thanks for your insights

 

Im trying to diagnose a similar issue. Driving home from work last night, truck seemed it was looking power. I pulled off to the side of the freeway and realized my front brakes seemed to be engaging and dragging, like I was pressing the brakes, but I wasn't. Brake pedal was hard as a brick and had no give. I pulled the brake booster vac line and felt plenty of vacuum. After a few minutes sitting, I was able to move the truck forwards and back, but had no braking power at all. Pedal was still solid. Couldn't even stop forward motion from idle. So I took a tow truck home. At home, at loosened the bleeder valves but wasn't able to to get anything substantial out (slow leak) or bleed the lines. Brake pedal still wont move, with or without vac line attached. Brake fluid reservoir is full. I jacked up the front and was able to freely spin the front wheels. Here it is the next day after sitting all night and pedal still wont move. Pedal will not depress while engine is running, not running or any combination in between. I recently replaced a bad master cylinder about 5 months ago. Thinking now I also have a failed brake booster. Anything else I can try or is that pretty much a failed booster? Collapsed brake line? How to test?

95/3.0/Auto/ABS/

 

I did finally get mine figured out, after dumping over $300 into a complete new brake system, all along it was the wish bone at the pedal, LoL, adjusted two turns inward, to allow the master cylinder to come to full rest, no more issues,
Thanks for the info, you set me in the right direction

 

I would try to adjust the wish bone under the dash, mine was a solid pedal as well, after sitting over night, it was like I had no pedal, it would go to the floor, but after driving a while, the pedal started getting harder, the engine would get real sluggish, I had to force the truck home one night in first gear, just to make it back, but as I stated above, once I pulled the pin under the dash, I turned the wish bone inward two turns, in turn that allows for the shaft in the booster to set back farther, I very no more issues with it, just wish I would have been smart enough to ask questions sooner.

 

Got rid of the shell, replaced it with a set of roll bars

 

Got mine sorted out rather easy. Bad MC. Looks like that snap ring failed and got jammed into the piston. Warrantied the part and replaced. Back to a working braking yota.





-Cheers