bob of the rockies

By the time I decide to replace my engine I had already put 5 grand into the machine. Having no brakes I methodically replaced every component in the system but ended up having brakes as bad as the original. I took it to a mechanic and he said he done a compression test and it was reading 213-217 when it should be reading 230-250. I confirmed. The mechanic also said the vacuum to the booster was low because of the compression being so low. After replacing the engine I still have a brake problem, I haven't checked the vacuum yet and the new engine has less than a mile on it.

Thanks and any insight would be helpful.

foxmxrcer

I'm not good at sugar coating....but...you got ripped off, those compression numbers are more then fine. Can you explain your brakes more? Mushy pedal? Hard pedal? Have to put it the the floor to get any brakes? What did you replace exactly?

bob of the rockies

I didn't get ripped. I got the great satisfaction of working on my own vehicle...hmmm. And it had 140 thou on it. It was due.

I replaced everything in the brake system except for the steel lines. When bleeding I found no obstruction. I replaced the booster and the master twice (under warranty).

My brakes hit very near to the floor and I get no stopping power whatsoever. When I get done trying to align the exhaust (another story) I will check the vacuum to the booster.

foxmxrcer

Does it have abs?
And did you bench bleed the MC before installing it. Also, when bleeding the brakes, are you getting fluid? A little bit?a lot? Bubbles? If you turn the Jeep off, pump the brakes a few times, then press the pedal down, does three pedal sink add you hold pressure on it like there is a leak?

freegdr

Rear brakes adjusted yet ? Front calipers bleeders on bottom ?

McCaffrey

I see you have an 89 (same as mine). What size tires? If you're running 33ish" or larger you can expect the brakes to suck with stock components. Unless you start doing mods you have no option other than OEM pads and crappy brakes.

freegdr

There crappy with stock tires..Double diaphragm booster upgrade best upgrade ive done by far.

Parsnip

Does it have a 35 rear? If so you got seriously ripped off. Your ABS motor probably went dry. Take it to a good mechanic or find out how to run the ABS motor to bleed it.

McCaffrey

Agreed. I did the ZJ booster/master-cyl upgrade too. Definitely worth it. Next is to swap in later model knuckles so I have a choice of aftermarket pads. My buddy did a rear-disc conversion but I doubt I'll go that far.

freegdr

Next time im doing rear shoes im doing it got a 96.5 8.25 410 gears in mine.

DFlintstone

Like said, all else in order, the pedal free-play is directly linked to the adjustment of the rear shoes. The auto adjusters barely work, if at all.
I go through the slot, adjust them till its pretty stiff, then back it off, pressing the brake to seat them now and then.

Also like said, the bleeders on the calipers go up. The calipers will actually fit on the wrong side, upside down.

McCaffrey

Going through that hole on the rear is next to impossible for mortals. I take off the drum, adjust until I can almost not get the drum back on.

bulrid8

Going through the hole is easy. A flathead screwdriver and a few minutes each side.

About as easy as it gets.

Adjust rears and bleed and bleed and bleed again.

Most brake problems are from those two things.

DFlintstone

You do know there is a tool. Vaguely like a small, drop-forged spatula.
If you have any lip at all you are gonna end up with more play in your petal. Ok I guess, but it sure feels nice to have it right up, solid! (it really maters, that adjustment)

McCaffrey

Yeah I have a couple of the tools but I'm just way to lazy to learn to use them I guess. Jack, tire/drum off is just way quicker for me.