No front brakes after replacing front calipers (1 Viewer)

[AL76fj40]

I replaced the brake calipers in the front on a 76FJ40 and now have very little brake fluid going to the front brakes. It has rear drums that have lots of pressure, I bleed brakes on all corners. I believe the proportioning valve is preventing fluid from going to the front and have not been able to reset it.
I've started the 40 and pumped the brakes and do not have enough pressure to drive the pistons on the front calipers.
Any recommendation on how to reset the proportioning valve or do I need to buy a new one from City Racer?

 

[brian]

probably all gunked up.
just replace it. then open it up and be amazed the brakes worked at all

 

[AL76fj40]

Thanks, I'll do that. I haven't driven it in 15+ years so I got it back on the road, My 15 year old sone painted it and helped.

 

[sodafeld1]

Something similar happened to me on my hj75 when I put on new calipers. If the calipers, even when new, have been sitting around on the shelf for awhile, the pistons kind of seize, they need to be flushed with full contraction and full extension. Also, apparently, the fresh internal surfaces of the calipers can hold little bubbles of air when reacting to new brake fluid for the first time.

I thought it was the lspv too initially.

It is a good time to replace your master at the same time, as pumping the brake pedal to extend the caliper piston, can also extend the master cylinder further than what it usually has done before leaving it susceptible to exposing rust spots within the old cylinder. Not necessary, but best practice, a new master needs bleeding too, due to the bubble theory.
By fully extending and contracting the caliper pistons to max it lets the cylinders open and close fully for the first time. Can use wide mouth pliers to fully contract. I used some thin ply for the full extension rather than squeezing against the rotors, so I knew the piston could well travel beyond the thickness of the new rotors, really squeeze it.

I love the motive power brake bleeder, it is better than pedal pumping imo.
And of course, it is a good idea to have a look and clean up the lspv and your drums. Then you know, you can STOP!

Heard a story recently that some modern cars are going back to rear drums as they are so long lasting and simple.

 

[B y r o n]

Are you running a factory proportioning valve or aftermarket? The reason I ask is because mentioned that it may be restricting fluid flow to the front brakes. The proportioning valve is supposed to restrict flow to the rear brakes to keep them from locking up before the fronts.

 

[AL76fj40]

Are you running a factory proportioning valve or aftermarket? The reason I ask is because mentioned that it may be restricting fluid flow to the front brakes. The proportioning valve is supposed to restrict flow to the rear brakes to keep them from locking up before the fronts.

Yes, factory proportioning valve.
I've ordered a replacement. When I bled the rear brakes I got a lot of sludge.