Brake Bleeding - No Fluid to Left Front Bleeder Screw (1 Viewer)

[4Cruisers]

My son and I were bleeding the newly re-installed brake system on my '86 FJ60 last night. All of the lines were removed and cleaned (and blown out with compressed air), new flex hoses were installed, new wheel cylinders were installed in the rear, and remanufactured calipers were installed in the front - basically started with a dry system. We had previously bench-bled the master cylinder. The left rear and right rear brakes went as planned, but when we got to the left front caliper no fluid was getting to the bleed screw, and the fluid level in the master cylinder reservoir wasn't dropping, even after 20 to 30 pumps. I didn't think to put the end of the tubing from the bleed screw into a container of brake fluid to see if air was coming through the lines/caliper, but if it was I would have seen the master cylinder reservoir level drop, right?

This morning I was going to start by disconnecting the hard line to the caliper and see if I get air/fluid to that point. If not, I was planning on going back sequentially through each section of hose and tubing until I get to the tee on the axle housing - I did verify that I'm getting fluid to the right front caliper blled screw. Is tht a good approach? Or is there an easier way to find the problem. I need to get this figured out ASAP, I'm hoping to finish my build in time to take the FJ60 to Pig Party 2018 at the North Rim of the Grand Canyon next Monday, complete with the required FJ55 grille zip-tied to the front.

Any help will be greatly appreciated.

 

[OSS]

If the bleed screw is open at the caliper and you can pump the brake pedal to the floor over and over again with a reservoir full of brake fluid yet no fluid eventually flows out of the bleed screw at the caliper and the fluid level doesn't drop in the MC, the problem is the MC. Possibly air.

 

[4Cruisers]

Thanks, I'll take a look at the master again. It was fine for all three of the other wheels. What could have happened in between (in less than an hour)?

No obstruction in the last bit of hard line, and I have fluid at the tee on the front axle housing. A quick check for obstructions in the long tube on the axle housing and I'll button things up and go back to the master.

 

[Seth_O]

If the brake pedal was pumped aggressively during bleeding it could have scored the MC wall or damaged the internal seals.

This happened to me when I rebuilt my '80 brakes. Everything was going great then my helper got a little too aggressive/excited towards the end and I ended up replacing the MC.

Lesson learned.

 

[WildernessRimFab]

If the brake pedal was pumped aggressively during bleeding it could have scored the MC wall or damaged the internal seals.

This happened to me when I rebuilt my '80 brakes. Everything was going great then my helper got a little too aggressive/excited towards the end and I ended up replacing the MC.

Lesson learned.

This has happened to me in the past as well. @Seth_O may be on the right track.
Spend the 55 bucks on a motive products power bleeder to avoid this problem in the future. No more pumping the pedal and scoring the seals. The brake pedal normally moves only a couple inches, and crud can accumulate further down on the MC wall. When you pedal bleed and pump the pedal to the floor, you are dragging the MC seal past a portion of the MC wall where crud is accumulated and it doesnt normally travel.

 

[4Cruisers]

I found the problem, now I need to see how best to fix it. I have a 10mm nipple (from my el-cheapo master cylinder bleeding kit) with vinyl tubing attached to the elbow fitting that's riveted to the back of the brake backing plate, on the caliper side. And the flexible hose that runs to the axle tube is diconnected from the elbow. I attached my hand vacuum pump, BTW a tool everyone should have, to the other end of the tubing. Guess what, it holds vacuum. So there's definitely blockage in that elbow. I refurbished my FJ62 donor vehicle's backing plates, including de-rusting and a fresh coat of paint. I had put a bit of paper towel in the openings of that elbow before painting, and maybe some is still in there blocking things up. I'll hit the vinyl tubing with compressed air and see what I get. Hopefully that's the issue. In any case, a lesson-learned: When re-doing a brake system, or parts of one, make sure all of the passages are clear and clean!

 

[red66toy]

I had this exact thing happen to me when redoing the brakes on my FJ62. I had fluid to the Left front Caliper but nothing would come out of the bleed screw. All other wheel cylinders and right front caliper bled great. Ended up doing a warranty replacement on the Toyota Reman caliper. Replacement caliper bled and worked perfectly.

Edit--- never mind. Glad you figured it out!

 

[4Cruisers]

Ok, I got it . Hit the end of the vinyl tubing with 100 psi from my air compressor - something came violently shooting out of the elbow towards the wheel on the passenger side, but I can't find whatever popped out in my messy, cluttered garage. What I need is a BARN like Jimmy @CenTXFJ60 and @ceylonfj40nut. Now to re-install everything and try again. My son is willing to drop by during his lunch hour to go at it again.

 

[Seth_O]

Congrats on finding your issue! its a satisfying feeling when you have a problem and can identify a specific issue as the cause. How does the inside of the elbow look? Clean or rusty/gunked up?

Glad it was an easy/cheap fix.....

 

[4Cruisers]

Looks clean now!

 

[Infinity00]

Thanks for posting the resolution.

Regarding the motive power bleeder @WildernessRimFab is there one made for our trucks, or are they generic enough to work on all types of vehicles? Do you have a part number?

 

[CenTXFJ60]

Ok, I got it . Hit the end of the vinyl tubing with 100 psi from my air compressor - something came violently shooting out of the elbow towards the wheel on the passenger side, but I can't find whatever popped out in my messy, cluttered garage. What I need is a BARN like Jimmy @CenTXFJ60 and @ceylonfj40nut. Now to re-install everything and try again. My son is willing to drop by during his lunch hour to go at it again.

John, I lose my own tools and find them weeks later in another part of my barn. It's a total mess in there

 

[JMJA]

Thanks for posting the resolution.

Regarding the motive power bleeder @WildernessRimFab is there one made for our trucks, or are they generic enough to work on all types of vehicles? Do you have a part number?

The website has adapters you can purchase for the power bleeder. Domestic and foreign. You could call them and ask what adaptor you need.