You ever forget how you built something? Hydroboost

[barronj]

I swear, I have a terrible memory about some things. I remember that I cobbled together everything about my hydroboost system. The hydroboost came from one thing, the master cylinder from another, the PS pump from something else... argh!

The only reason it matters is I fired up the truck for the first time in a few months (it's been hot in Texas) and the pedal went to the floor at the first stop light. I was able to drive it around, carefully, I had brakes, but only at the very end of travel, near the floor.

Power steering was still there, so my assumption is it's my MC that's gone bad?

Any tips appreciated, been a long time since I contributed anything to the site, the bronco hasn't needed a wrench turned and my attentions turned elsewhere :^\

 

[toddz69]

Sounds like it could be a master cylinder to me as well if there are no leaks. Looks like an Astro van master to me.

Todd Z.

 

[EPB72]

Appears Astro van set up….. check for leaks , try bleeding at each wheel to see if gets better , but more then Lilly master cyl issue .. fluid full??

 

[barronj]

Awesome, that rings a bell. What years for the Astro Van?

Will check fluid on front res, rear is full though.

 

[barronj]

Also, while you two are eyes on, my pedal never returns fully, like i need to install a tension spring that I'm pushing against, a spring that would bring it back to the top of travel? When I put my toe under the pedal and lift it, the brakes fully release. Otherwise, there's always a pressure remaining after I brake. I can feel the drag when I take off again.

 

[toddz69]

Also, while you two are eyes on, my pedal never returns fully, like i need to install a tension spring that I'm pushing against, a spring that would bring it back to the top of travel? When I put my toe under the pedal and lift it, the brakes fully release. Otherwise, there's always a pressure remaining after I brake. I can feel the drag when I take off again.

That often means there's a restriction in the low pressure line from the booster to the pump. Make sure that's all free and clear. I'm sure there isn't any binding in the linkage but may way to check that too just to be certain.

Todd Z.

 

[barronj]

I was thinking the linkage might be the issue. Thanks Todd.

 

[Madgyver]

If changing the MC, Go with a 77 corvette master cylinder.

 

[barronj]

If changing the MC, Go with a 77 corvette master cylinder.

Thanks for the recommendation