Brake Booster Refresh (1 Viewer)

hoser

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1998 LX with original brake booster. 23 years old and 190k miles. No signs of trouble but I was concerned it would be just a matter of time given other peoples experiences. I was given the opportunity to test fit an aftermarket, booster motor and pump assembly from City Racer LLC. (Thanks @Racer65 ) I was able to get it installed and put a some miles on it.

I will say everything went well! I also installed the M/C rebuild kit.

If you want to do the same, here are the parts needed:

(1) City Racer Brake Booster Motor
(1) M/C Rebuild kit <04493-60330> All Years
(1) Brake actuator hose <44571-60010> All Years
(1) O-Ring for Accumulator <90301-13014> All Years
(2) 32oz cans of Dot 3 or 4 brake fluid

For booster removal, I looked over the FSM and then pretty much followed @Skidoo excellent M/C rebuild thread HERE.

Now for a bit of ugly.... which I expected to see since it seems to be universal. @2001LC has posted a lot of good information on it and boosters.


IMG_0108 2.JPG


Those screws had to be drilled out. Upon re-install, I sanded the contacts, generous dielectric grease and drilled a hole at the bottom of the rubber boot for drainage.

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hoser

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Here are some comparison pictures of the original and City Racer's booster motor/pump assembly. There might be some changes though. It has been said, there are some improvements that were made over the OE unit.

"There are 2 key areas, which I'll elaborate on after the part goes live. One is the heat dissipation hole on the OEM unit that allows water and oil to enter and contaminate the electricals. We moved the location of this hole to mitigate the issue. Second has to do with an area inside the alloy section of the pump where the factory machining process has tolerance control issues. That's why some OEM pumps last longer than others."

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I'm a die hard OE replacement parts guy but I can tell you the fit and finish of this unit is very good. There was a slight issue with the electrical screw connections being too long but I think that'll be remedied in future units.

Only time will tell but I will certainly feel more at ease when I will travel to remote areas this year. I believe the two most common failures within the booster unit is the electric motor and M/C. I've replaced those both. The accumulator is also probably a wear item but I haven't heard much of it failing on mud. If you have a failed booster, PM @2001LC ... (are you still examining them?)
 

hoser

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Rebuilt is certainly option... the quality is dependent on the rebuilder and how many parts they replace. This is a half to one day job with the part in hand. Having your original unit rebuilt could take 5 days? a week? I dunno. It is my understanding that some of these internal parts are actually from an OEM supplier.
 

Somebodyelse5

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Rebuilt is certainly option... the quality is dependent on the rebuilder and how many parts they replace. This is a half to one day job with the part in hand. Having your original unit rebuilt could take 5 days? a week? I dunno. It is my understanding that some of these internal parts are actually from an OEM supplier.

What does their booster cost? Couldn't seem to find the one you used on their website.

If it's comparable to a the rebuild in price, i'd say it's a no brainer to go with the new one. I was about to send my unit out for rebuild while I had my calipers off for rebuild, but I decided I didn't care that much.
 

JunkCrzr89

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What does their booster cost? Couldn't seem to find the one you used on their website.

If it's comparable to a the rebuild in price, i'd say it's a no brainer to go with the new one. I was about to send my unit out for rebuild while I had my calipers off for rebuild, but I decided I didn't care that much.
Based on how much their 16” 40 series wheels cost (but worth every damn penny!), I’d say Euroton Electric rebuild will be a few bones cheaper.
 

flintknapper

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I went with a new motor and accumulator, but the windings and bearings in my old booster motor were good. Brushes were gone, there was significant wear on the commutator and I poured a LOT of carbon out of the inside of the motor.

It seems the two most prevalent issues are brush wear and corrosion of the screws both at the motor and the ABS unit.

Mine were terrible and my vehicle has been a Texas truck its whole life.

The rubber boots on the wiring harness are there to prevent arcing IF anything stray should come in contact with them. Trouble is....they create a situation where condensation forms underneath them and they also don't fit quite tight enough to keep atmospheric moisture from entering or rain water, etc...etc...

A drain hole may or may not help.....I suppose time will tell.

I believe copper coated fasteners (nuts and screws) would go a long to prevent the rust type corrosion we see. Copper has its own issues but at least you can clean it.

Corrosion1.jpg


ABSmotor4.jpg

ABSmotor8.jpg

ABSmotor9.jpg
 
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Just curious, can the rubber covers be popped off to inspect the condition of the screw connectors with the entire unit still mounted in position in the truck? Or are they too inaccessible ?
 

hoser

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@badlander Yes, you can inspect the terminals with the unit in place. You'll need a small mirror. The terminal on the ABS side is the problem.

**Also note how the wires are zip tied so they don't touch the red brake lines. Be sure to do that upon installing a new motor. I suspect the brake lines can get pretty hot but I've never measured.

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This is the terminal on the motor side. It is oriented sideways. I suspect any moisture self drains versus the rubber "bowl" on the corroded end. Mine was clean... not sure of other people's experiences.

IMG_0113D.JPG
 

hoser

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Noteworthy, on City Racer's motor, there are no exposed terminals on the motor side. The connection is inside the unit.
 

abuck99

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Thanks @hoser very helpful thread. Good to know theres an aftermarket option coming.

Interesting subtle differences in the original OEM MC piston vs the replacement OEM MC piston-beyond the pretty red anodizing, the ramp area is now tapered- not sure if that has any impact on anything but its different.
IMG_0131D.JPG


Regarding the differences in the aftermarket booster:
Have you noticed a difference in system priming time? longer than 30 seconds, or less than 30 seconds?
From the side by side comparison it looks like the motor is slightly smaller (shorter) than the original. Is that the angle of the image?

Last-@Racer65 can you explain the improvement differences in more detail of your booster compared to the OEM unit- what findings did you notice in the OEM unit that reading machining and tolerances that caused early failure? Where is the heat dissipation hole?
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hoser

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I noticed that too about the M/C. Does it affect brake bias any? The bottom of the piston is also different in length.

As for priming time, I have not measured it but it is short, for sure under 30 seconds. When I get a chance, I'll time it.

The motor size looks roughly the same size. I can tell you the mounts are in the same position and line up perfectly on both planes. The lower mounting bracket pictured on the City Racer motor was transferred over from the OE unit.

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