77' FJ40 front brake issues

[rckhound]

So I went to swap some wheels on my newly aquired 77 fj40 and when I jacked the front end up and got the wheels off the ground a spun them to get a feel for the bearings and they take some pretty good effort to spin by hand using a 33" tire. Its like the disc brake calipers are holding some pressure. The brake system apears to be all stock with drums in the back and some upgraded stainless lines. The truck had 20,000 miles put on it since 1999. I have driven it almost daily for a couple weeks and was getting some squeaks from the front but didnt think to muchof it. Anyone come across this before? Bad stock proportioning valve? Can I bypass it with and aftermarket willwood? Thanks, Steve.

 

[Hulk]

Are you sure it's brakes? Could be an overtightened wheel bearing.

 

[rckhound]

Brakes

Feels and sounds like brakes.

 

[Rzeppa]

It is normal for stock 77 front disks to have a bit of drag when you spin the wheels. Do the front calipers work when you stomp on the brakes? If so then at least they move. Older rigs can have calipers that don't move freely. A good inspection seems warranted. It is doubtful that the proportioning valve is a problem, they seldom malfunction. More likely, you either have normal front calipers or perhaps calipers that don't move freely. In the latter case, simply removing them and sanding the rust from the pins can be helpful. Otherwise, rebuilding or replacing the calipers would solve your problem.

 

[rckhound]

Brakes

They definately have way more drag then normal. Brakes have been operating normally except for one night Inwas getting a hissing sound and the pedal was dropping quite a bit like it was loosing vacuum. Hasnt done it since. It takes some good force to spin the wheel with the 33 on and when it was off I could not spin the hub assembly at all by hand.

 

[kurtnkegger]

Are both sides difficult to turn, or is it just one side? I would suspect the master, or check pedal travel to make sure the pressure is off of the master if both sides are binding. Especially after you described the hiss / vacuum leak scenario. If only one side, I would guess it's a caliper issue.

 

[rckhound]

Its both sides with equal amount of drag.

 

[Rzeppa]

Its both sides with equal amount of drag.

That might implicate the master more than calipers.

 

[ToyodaTocco]

Unbolt the calipers and put them aside, then spin your wheel and see how that feels. What do your rotors look like? Are they blueish in color and have a heat cracks on them? Also check any swelling of rubber brake lines

 

[SteveH]

My '78 FJ40 calipers after 30+ years were gummy inside. I rebuilt them with an OEM Toyota kit, and the pistons were covered with gooey brake fluid and sludge, but no rust. The brakes seemed to feel better (respond more quickly) when I was done with the caliper rebuild, but I'm not sure if my gummy pistons were causing brake drag or not.

They were a pain to rebuild, so I'm not sure I wouldn't recommend just getting reman calipers, rather than rebuilding yourself. It wasn't hard - just time consuming and messy and frustrating to try to blow out 4 pistons at once.

 

[rckhound]

Yeah my next plan was to unbolt the calipers and spin everything. May just order a master and replace it for good measure. The truck definately sat a lot since 99 and the brake fluid is not a good color. Beake lines look good and like most of them have been replaced.

 

[Rzeppa]

It wasn't hard - just time consuming and messy and frustrating to try to blow out 4 pistons at once.

There are lot of Land Cruiser projects that are like that...that's why I sometimes opt to just buy new (or reman) parts to save time and sanity.

 

[rckhound]

Replaced the master and it wasn't the master. Picked up some new calipers so Ill give that a try next. Just wanted to give an update.

 

[kurtnkegger]

How is the return on the peddle? can you pull back on it and get more return? Is the spring OK?

Just some simple things to check.

 

[White Stripe]

I'm going to bet money the hose from the frame to the axle is bad. Crack the line a bit where the hose meets the axle hard line. Then see if your wheels spin freely. If they do, u have a bad hose. It's unlikely for both calipers to be bad. Let me know what happens. If their still stuck their are further steps to take I Can give u

 

[rckhound]

New calipers seem to be working. Havent driven it yet, but I stomped on the brakes several times and its not holding pressure like it was.

 

[rckhound]

One of the calipers was visibly bad. Ao e of the pistons was stuck enough to wear a pad all the way to metal on one end and was at least half pad on the other end.