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Discussion Starter · #481 ·
Ed Mc. said:
Success, hooray!
Thanks Ed. Could not have done it without you and the other guys. Engine runs and drives just like I remember those little Japanese 4 bangers form the 80's were supposed to run.

Beyond thrilled right now and punting my idea of switching to a carb...............................at least as long as it keeps running this way! :D
 

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1989 Trooper R/S
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giusedtobe said:
I've been enjoying the usable Trooper the last few months and catching up on neglected projects so I haven't done much to the old Troop lately.

In the vein of NOT being a parts changer I tried multiple tests to isolate the rich running condition and the starting issue. All to no avail and the tests showed a functioning MAF even though it did not behave like it did. Fast forward to a week or so ago I decided to lump it and buy the expensive refurbished MAF assembly from Rock Auto. Damn thing was ~$100. Remember I had already bought their aftermarket MAF sensor and it did not fit nor work.

Dennis sent me one from his old truck and I installed it and the problem was basically the same. So I had tried three different MAF's with same result.

Installed the pricey one today, fired it up and all I can say is WOW! Honestly I was expecting no change but it ran like a top. Not running rich at all. The starting issue is gone and it had much better power with no misfiring or stumbling. I am beyond elated and did I mention no check engine light!!

Now this is what I was hoping for after rebuild. Thanks again for all the help you guys have offered on this project. Thought you might be interested in an update. Now its time to move on to the chassis & I'll post changes as I make them.

Regards,
Alan
Great. When electronics was introduced into mechanical systems ITEC) With engine parameters controlled by basically a computer, troubleshooting sometimes simple problems became more involved and also sometimes totally frustating. Great, because you stuck with it and the end result is as I said, Great.
 

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Discussion Starter · #483 ·
Moving on to new projects with the old Trooper and of course spending WAY too much money! These are labors of love though as they will never hold the value that you put in them. I recently bought a new/old round eye grille and parts and also a new/ old original dealer installed brush guard.

Latest problem which is not really unexpected is the brakes. They worked fine but now the pedal gets spongy and sometimes you have to pump it a bit to regain pressure. I haven't cracked it so I doubt its air in the lines and the master cylinder is full with no signs of leaks. Talked to another Isuzu guy and he said he had a problem in the brake booster and now I'm wondering if this is my problem. I've never fooled with brake boosters and was planning to replace all the pads & potentially rotors but I'm kind of doubting that they are the problem right now.

Anybody have the skinny on how to test the brake booster or trouble shoot the master cylinder?

Thanks
Alan
 

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Hey Alan,
I'd start by bleeding brake lines.
If you do replace a calliper DTR you'll do this anyway.
Check lines to ensure no leaks first.
Suprising the horror inside of a neglected brake fluid line even when master looks decent and is full.
Get a bottle and gravity bleed them.
Approximatly one beer per corner
 

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Could be a faulty master cylinder (bypassing). Try this: With engine running, press down on brake pedal. Now let up just slightly while keeping light pressure. Does it sink? Often, they will go all the way to the floor. That would be a sure sign of a bypassing master cylinder.
As a note. These trucks are 30 years old (or older). Most have never had the brake fluid changed, so all the funk and any moisture (brake fluid attracts moisture) is in the system. Fresh fluid and a flush is a good idea for any of these vehicles. Back when I was doing British Land Rovers, almost every Rover we drug up had bad brakes (NO brakes). We found out the service recommendations called for brake fluid flush every 3 years AND replacing rubber seals in cylinders (4 wheel drum brakes with GIRLING components). Dennis
 

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Discussion Starter · #486 ·
Thanks guys. I haven't even dug into it yet but will this weekend. The fluid is gross and definitely needs to be flushed out and replaced.

Dennis I'll try the test you describe but when you say bypassing the master cylinder do you mean the fluid is passing around the cylinder kind of like oil blowing by worn rings?
 

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Exactly. Often, if you hold down hard, it will seal. Otherwise, it leaks past the seals. Dennis
 

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I replaced the master cylinder on my spacecab a few years back because of those symptoms. No issues since.
 

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Discussion Starter · #489 ·
Yeah it did exactly what you said so I guess the master cylinder is bad, mo money mo money!

Dumb question" where the heck is the fluid going thats bypassing the piston? Its not leaking out of the system as far as I can tell.

How can you tell if the brake booster is working correctly?

There are some wires coming off the master cylinder reservoir, what are these for? Mine has one broken off.

Thanks
Alan
 

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The fluid is swishing back and forth in the cylinder. What "oozes" past the seals makes it's way back into the reservoir section when the pedal is released. When they get REAL bad, it starts leaking into the section between the booster and the cylinder.
The wires should be for the brake fluid warning system, which is a float and switch. Dennis
 

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Discussion Starter · #491 ·
I've had it on jack stands for some time now but I rebuilt the front calipers and they were not bad at all. Just a tad of scoring in the bore but the pistons looked good once cleaned up. Now I have to figure out how to do the rear calipers. It looks like they thread onto the parking brake actuator? Also looks like it takes a special tool of some sort to turn the piston once its seated? Anybody have any tips on the rears?

Hoping the brake booster is good.
 

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giusedtobe said:
I've had it on jack stands for some time now but I rebuilt the front calipers and they were not bad at all. Just a tad of scoring in the bore but the pistons looked good once cleaned up. Now I have to figure out how to do the rear calipers. It looks like they thread onto the parking brake actuator? Also looks like it takes a special tool of some sort to turn the piston once its seated? Anybody have any tips on the rears?

Hoping the brake booster is good.
Yeah, you need a special tool to wind-in the rear caliper piston. This $20 set at Walmart would do the trick:

https://www.walmart.com/ip/18Pcs-Univer ... lsrc=3p.ds

There are Jillions of these generic kits on eBay and Amazon as well.

There's an older-style tool that's just a metal cube, with 3/8" squares on each side to take a ratchet, and different pin patterns on the various sides of the cube. These are OK, they get the job done, cheaper too. The "winder" kits like the one at Walmart would probably be a easier to use.

This one is under #10 and Lisle Tools are good-quality: https://www.amazon.com/Lisle-28600-Disc ... B0002SQUFY

Or, some ZuZu Dudes just wind 'em in with a pair of needle-nose pliers. It works but rather tedious.

Hopefully your rears are in good rebuildable condition, they can get a little $pendy online, with a core charge on top of that.

Rockauto has a $7 rebate ongoing for their AC Delco rear calipers. $24/each refundable core charge. When I had a sticking rear caliper I just ordered the rebuilt one at Rockauto, I didn't want to mess with it.

Rebuild kits are dirt cheap, if you want to save some $$$. Return shipping for the caliper core(s) is free, and they're pretty good about sending the rebate out quickly.

HTH.......ed
 

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Discussion Starter · #493 ·
Hmm........the needle nosed pliers sounds right up my alley!

So when putting the piston back in you just bottom it out and then give it a few turns? When I popped it out with compressed air it cam right out.

Should have the rebuild kits for the rears tomorrow.
 

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Definitely gotta be patient for the needle nose pliers method, they have a tendency to keep slipping off when youre applying torque and you end up having to do tiny turns at a time since the tips are rounded. I have this style (not sure what brand) that you just plug a socket extension into. Still not perfect but A LOT easier when you find the right side to use.
 

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giusedtobe said:
Hmm........the needle nosed pliers sounds right up my alley!

So when putting the piston back in you just bottom it out and then give it a few turns? When I popped it out with compressed air it cam right out.

Should have the rebuild kits for the rears tomorrow.
I think the parking brake adjusting mechanism screws into the piston. The manual says to turn it clockwise with a bit of a push. I'd think you'd just make sure it was bottomed-out on the piston before reassembly. Each time you apply the parking brake, it'll automatically turn its way out of the piston, to compensate for brake pad wear. I've never had one that far apart before, post a few pics if you get a chance.
 

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Discussion Starter · #497 ·
DSUZU said:
About halfway down page 38 of my build thread shows how I modified an extra spark plug socket to make it a caliper tool.
https://forum.planetisuzoo.com/viewtopi ... &start=925

Dennis
That's a great idea! I tried the needle nosed pliers on the one rear I had not disassembled to see if I could turn it back in and it was tight.....wouldn't budge. On the other hand the one I disassembled was pretty easy to bottom out with the pliers. I was going to clean up and rebuild the other one anyway. Not sure I understand how these work since the piston screws down on the actuator like that. Does the brake fluid pressure unscrew it as the pads wear?
 

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Discussion Starter · #498 ·
So I am one for two on the seating the rear caliper pistons. One went in real easy with the needle nosed pliers. The second one got about 3/4 of the way in and will not budge, at least not with the needle nose pliers. Not sure where to go from here, I don't think it should be this hard to turn.
 

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Usually with "stuck" screws (bolts, whatever) I loosen as much as possible, apply WD40 (or whatever) tighten and loosen again. After a few times they usually free up. Dennis
 

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Will that thing screw all the way out of the piston? You'd think it should. I've never had to have one apart. If you can take it all apart, then you can clean up any Crud within. Should make it work better.

My other thought, is the threaded portion supposed to have any lubrication on it to keep it from seizing? Maybe some good ol' anti-seize compound? A very sparing coat, of course.
 
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