Separate brake system thread... air trapped, and with the best effort we can't get...

[toddz69]

The original plan was to throttle the larger bore caliper down with the brake bias valve I've been using since I put discs in the rear back in '99...it has dialed in several different caliper sizes so...

Caliper choice was dictated more by the rotor that fit the 14 bolt spindle setup... allowing for the fact that the T-bird caliper and JB7 are very similar bore size...JB7 is appr .1" larger OD.

The JB6 & 7 calipers mouting pin/bolt are appr 7" OC. Most others are closer to 5+"... I might have to redo the caliper bracket setup and run smaller piston calipers also...

Yeah I figured there weren't too many caliper choices. Focus on getting those brakes working well as is and then refine as needed, I suppose .

Todd Z.

 

[nvrstuk]

I got BRAKES!!!!

More later!

Thanks Steve!

 

[Yeller]

The unit that I mensioned runs 3.5" bore calipers so it should have more than enough volume. I have a buddies bronco that is running the 3.5" bore calipers front and rear with that MC and hydroboost and it's has good feel and way lots of brakes to spare

 

[toddz69]

The unit that I mensioned runs 3.5" bore calipers so it should have more than enough volume. I have a buddies bronco that is running the 3.5" bore calipers front and rear with that MC and hydroboost and it's has good feel and way lots of brakes to spare

What calipers have a 3.5" bore? I'm not familiar with them.

Thanks,
Todd Z.

 

[73azbronco]

How are you bleeding the lines? I once had issue with a vacuum bleeder sucking air past the diaphragm in the brake cylinder. Basically to much suck, tried it again real slowly and it worked.

Hate to say it, sounds like MC is not properly bled or is an issue internally leaking. Even with incorrect bore you should get a firm pedal at some point unless its just totally incompatible.

 

[nvrstuk]

The mc I had worked great with frt 3.1" bore calipers and rear 1.8" rear calipers.

It did not have the capacity as a step up mc to feed the rears.

I (I should Darrin and I were starting to figure out that I needed more fluid capacity and was looking at larger bore, standard style mc's.

Steve posted that I should try the 1 ton mc that has 1.3888" bore and the mounting flange fit on my hydro boost and the rest is history....

It takes a full stroke of the pedal to move enough fluid to fill 4 big calipers but works great now.

Thanks all for your help and ideas!

 

[toddz69]

Good to hear!

So you still have to do a full pump, and then another pump to get brakes?

Todd Z.

 

[Skiddy]

good deal glad you got it figured out, I wouldn't have thought that's what it was.
now ready for Moab right

 

[Yeller]

What calipers have a 3.5" bore? I'm not familiar with them.

Thanks,
Todd Z.

Factory Chevy/dodge 1ton Dana 60 front calipers.


Woohoo BRAKES!!!

 

[nvrstuk]

good deal glad you got it figured out, I wouldn't have thought that's what it was.
now ready for Moab right

About 4 more 12 hour days and zip ties (which I'm not into but I don't want to miss another wheeling trip)!

Still have frame work to do on the RV, hitch etc...

Gonna make it to MOAB!! ( update upon return...last day to leave was Monday am..."finished Bronco" and left Monday at 4pm- but if you check out my build thread I had some MAJOR issue to overcome on Saturday)

 

[dclack]

Good deal! Sounds like we were on the right track Friday... not enough fluid to the rears. I bet if you put the JB6, S10, or Super Duty calipers on the rear you'd have even better pedal. But that's something you can leave for another day, after Moab.

 

[nvrstuk]

Good deal! Sounds like we were on the right track Friday... not enough fluid to the rears. I bet if you put the JB6, S10, or Super Duty calipers on the rear you'd have even better pedal. But that's something you can leave for another day, after Moab.

Sure appreciate ya helping out Darrin! I thought we got a lot done! ;D

Remember, I still have to bleed the brakes again later this week after I put the line locks and brake bias valves back in!

RIPPED the RV apart and started building a trailer hitch for it tonight.... you think I"d learn! lol

thanks again for all the contributions and ideas....

Here's the main build thread... http://classicbroncos.com/forums/sho...d.php?t=278607