Help!!! No Brakes!!!

[Joes4x4Ranger]

I've got a '91 4X4 4 door 93,000 miles. It has 4 wheel disc but I don't think it's ABS, no wheel sensors or control module, just a simple aluminum master cylinder with a plastic reservoir.

My brake pedal is EXTREMELY low and mushy. It will pump-up and hold, but as soon as I release and re-apply it goes to the floor. The pedal is nearly to the floor to stop the rig, but it does stop.

Does this sound like a bad Master Cylinder? Air in lines, (where would air get in)? Or could it be frozen caliper slides?

 

[quicklook2]

you do not have all 4 wheel disc brakes.

discs only in the front.

not offered in that year.

93 first year for abs.

too many variables to tell you exactly what is wrong.

could be: low on fluid, bad master cyl., leaking brake line, worn front pads, worn rear brake shoes. etc.

 

[marragtop]

Sounds like a bad master cylinder. But, check your rear brake shoes and parking brake adjustment. If the pedal gradually goes to the floor by interimetiment pumping, then it's probably the MC.

 

[Joes4x4Ranger]

It has 4 wheel disc. If this year did not come with it, the rear disc set up must be a jimmy rig. The rear axle assembly looks freshly painted. Could this be the main problem, incorrect proportioning valve?

What would it take to convert it back to rear drum? A simple backing plate & drum install, or is it more involved.

 

[wolfnutts]

with out pics its hard to tell maybe some one swaped in a rear disk setup from a 95 an up explorer if so ur better off keeping it. u may want to look at ur flex lines at all 4 wheels they may be bulging out from old age . chock ur wheel get under ur trk an have some one pump the brk pedal an see if lines blow up like a ballon )

 

[mikeinri]

Start with the simple stuff. Bleed all 4 brakes enough to have new fluid flowing through all the lines. If that doesn't correct it, you're looking at hardware.

Hope this helps.

Mike

 

[Joes4x4Ranger]

I started w/ the 4 wheel bleed, let the fluid run clear. Thats when I started askin. I'll do the line check today. It feels like rear drum brakes severely out of adjustment.
If the jack-offs that did the swap did not change proportioning valves, will I ever get the thing to feel right?

 

[Joes4x4Ranger]

Well I figured out part of the problem, some hack swapped in a Dana 35 W/disc brakes. It is a total butcher job, hard lines flapping in the wind, flex lines rubbing on the axle housing. The flex(rubber) is severely chafed not swelling.

The worst part is this vehicle was supposedly Safety inspected by the service department of Dealership I got it from. One thing for sure that dealership will never change a lug nut for me.

Is there any way this thing can be made safe? I put a new master cylinder on it, new front pads, and bleed & bleed & bleed the lines but the pedal still travels to the floor to stop this thing. Very low and mushy. I cannot see any signs of fluid leakage anywhere.

 

[quicklook2]

replace the flex lines.

 

[mikeinri]

You replaced the master cylinder? Did you do a bench bleed? I've seen threads here that discuss the need to do this, otherwise the system never
bleeds correctly.

As mentioned, flex lines also sound like a good idea to replace.

I haven't personally come across this problem yet, just trying to help you narrow down the possibilities.

Hope this helps.

Mike

 

[Joes4x4Ranger]

Yes I did bench bleed the master. I never install a "dry" master. How does the Dana 35 rear stack up against the Ford 8.8? I'm debating on if I should just get to correct rear end or keep trying to fix this jimmy rig Dana disc set up.

The swap was done by someone VERY VERY stupid and unskilled. It is a total butcher job. Hacks like that need to have thier hands cut off so they will never be able to butcher another vehicle.