Brake Bleeding - 91 EXP

[DsrtExplorer]

I just picked up a 91 Explorer 4dr/4WD with only 89K dealer serviced miles from my neighbor who is pretty old and didn't drive it much. I had a '91 that I sold a few years ago and when he mentioned this one was going up for sale I jumped on it. Its in good shape and everything seems to work, exept the stock AM/FM/Cass (that would go working or not!). While going thru it, I noticed the front brake hoses were cracking so I replaced them and decided to change out the brake fluid while at it. Using my Mighty Vac pump, the fronts bled normally, but I am not getting any fluid from the rears. I tried each side, then put a "T" in the line and tried both at once. When I pump, vacuum builds, but no fluid comes out. I am wondering if the rears are even actuating when I apply the brakes. The pedal is firm and the vehicle stops smoothly without a pull so the fronts at least are working fine. I did a search and the only comments I found say with the RABS, the system can be bled normally, but maybe I need to try with a helper and push on the brake pedal and see what happens. Any suggestions would be helpful. Thanks in advance for any help.

Ken
New (to me) 1991 Explorer

 

[arco777]

I did not have any luck using a vacuum pump to bleed my rear brakes when I did a disc axle swap. I used the Dorman Speed Bleeders and that was much easier. Just loosen them a little, pump the brake pedal while the fluid squirts into a container of your choice, and tighten them. No air bubbles thanks to the internal check valves.

 

[jd4242]

Could be a bad abs unit..mine was stuck closed, I had no rear also.I bypassed it.not uncommon for them to fail, they get rust in them and stick

 

[DsrtExplorer]

Thanks for the replies. I am taking it to the Navy base hobby shop tomorrow to use the lift to change the oil and get a good look underneath at things and I'll try a manual bleed then. If it looks like the RABS is blocking the fluid, I think I will bypass the unit. Funny thing, when I mentioned to my wife the suspected issue, she reminded me that I bypassed the RABS on the previous Explorer because it was leaking....I looked back at my maintenance log from before and saw that she was right. Does anyone know the size of the couplers I would need to bypass it? I would guess 3/8 with 24 thread, unless its metric. Thanks again for your help.

 

[intelisevil]

Thanks for the replies. I am taking it to the Navy base hobby shop tomorrow to use the lift to change the oil and get a good look underneath at things and I'll try a manual bleed then. If it looks like the RABS is blocking the fluid, I think I will bypass the unit. Funny thing, when I mentioned to my wife the suspected issue, she reminded me that I bypassed the RABS on the previous Explorer because it was leaking....I looked back at my maintenance log from before and saw that she was right. Does anyone know the size of the couplers I would need to bypass it? I would guess 3/8 with 24 thread, unless its metric. Thanks again for your help.

Important words to remember for any chance at a long marriage (almost 37 years here!).

Sorry, I can't help with the plumbing question.

Dan

 

[DsrtExplorer]

An update on the brakes. I had the left rear one grab once before I made it to the hobby shop, so I was a litlle confused by that, since no fluid seemed to be flowing before. On the lift I found that the rear rubber brake hose was looking pretty rough, so I changed it out. From the outside of it, I could tell the rubber had broken down pretty bad like the front ones. I could scrape away the outside of the hose with my fingernail, so I wonder what the inside was doing. The desert is hard on rubber things. Once I replaced the hose, the system bled normally. The mechanics of the brakes looked good, so I did a quick clean and adjust after the bleed, and put it back together. Since it was already dark when I was done, I just took a quick trip around the neighborhood and it seems better with a couple of hard brakings. I have some running around to do tomorrow, so I'll get a better test then, but I think it was that old degraded hose was causing me problems. It now has all new rubber brake lines, clean and lubed caliper slides, and new brake fluid since I flushed the rear until it ran nice and clear like I was putting back in. If nothing else, it has to be better than when I got it.

Intelisevil- I made sure to let my wife know I need her around if for nothing else, to remember things for me. Actually, the last Explorer was "her" Explorer" that she bought in 1992 and kept until 2009 so she made sure I kept it in good shape!

Ken

 

[DsrtExplorer]

Last update to my brake issue. After driving this morning, the brakes were still not exactly right. I came home and had the wife help with the old style pump the pedal and I laid under and cracked the bleeder and repeat. After a few cycles on each of the rear, the brakes are finally right. Arco777, I'll have to look into the speed bleeders, the vacuum method just doesn't work completely. Thanks for all the help on this everyone!

Ken

 

[jd4242]

I love the speed bleeders..worth it for sure