Brake Booster Going South + Interchange

[Kodachrome Wolf]

So this is what I’m seeing at work. The booster I got was for a ‘92 car; no ABS. However, it is shown as compatible with ABS/Non-ABS, non-Police boosters for ‘95-‘00 cars.

The difference between the police and non-police unit is only the diaphragm diameter. Police is 8.82in/224.03mm and non-police is 8.75in/222.25mm.

I’m not sure if the extra two millimeters is really worth the difference to swap the booster I got with the police booster.

Edit: The difference between the ‘92-‘94 Non-ABS booster and the ABS booster is the M/C stud size. The non-ABS unit uses standard threads shared with the earlier cars. The ABS boosters use metric threads. However, ‘95-‘00 cars use the same booster regardless if they have ABS or not since all boosters for those years use standard threads.

Nitty gritty of everything:
‘92-‘94 (‘90-‘94 TC) Non-ABS + ‘95-‘00 Non-Police Boosters are interchangeable as they are they same. Both use standard threads on the studs and have a 222.25mm diaphragm diameter.
‘92-94 (‘91-‘94 TC) ABS boosters are unique to themselves. They use metric threads on the studs and have a 222.25mm diaphragm.
‘95-‘00 Police boosters are unique to themselves. They use standard threads and have a 224.03mm diaphragm.

Sorry for the aimless information in my post, I’m at work and just trying to get the informational differences.

[gadget73]

244.3 square inches vs 240.4 square inches. Assuming vacuum pressure of 15 inches, (7.3 psi) thats 1783 lbs of force vs 1755 lbs. All in all, not enough to fuss over.

[knucklehead0202]

Ok so i'm going to threadjack a bit too! Mostly when cold, i get some idle surge when braking. Think this is a booster issue? The brakes are also super-touchy and the surging only exacerbates this. Reckon swapping the booster may help with this? M/C on the car looks to have been replaced in recent history but the booster, who knows....

[sly]

possible. sounds like the seal on the plunger may be a little loose when cold and seal up when warmed up.

[Kodachrome Wolf]

can you take a couple pictures from under the dash (booster nut area) and post them up please?

I really could not get an adequate angle up under there for photos. This is the best one I got.


Getting the old booster out was only challenging because of how large it is and the fact all the harnesses conveniently run across the booster. Swinging the cruise control unit out of the way and disconnecting a few vacuum lines aid in removal. The master cylinder doesn't need to be undone from the lines unless you're replacing it and I was able to adjust it forwards on the lines to clear the booster. It took some persuasion to wrangle that thing out from the harnesses and get it at the right angle to get it to clear since the wiper motor blocks it from coming straight out.

Failing booster:


Installation is easier than removal as far as fitment goes given the considerably smaller diameter. It took a moment to get the studs to slide through, but nothing had to be modified beyond just having the master cylinder a little farther forwards. Clearance with the air box lid and old style master cylinder is really tight, but it fits fine.





In the end, the brake pedal feels a lot better a bit more confidence inspiring. Originally it was incredibly firm and didn't have a lot of travel and brakes felt kind of grabby. Now when applying the brakes normally there's modest travel with good pedal feel and stopping power feels fine. Immediately applying the brakes in a hard braking application results in a very firm pedal with short travel, but plenty of braking effort and good pedal feel.

Personally, if someone has to do a booster job on car with the earlier booster, using the later one wouldn't be a bad idea given it's easier to install with the smaller size, parts availability is still good, and even used it wouldn't be hard to get the right one given you have such a large year range to work with. However, I wouldn't just go yanking out an old style booster if it's still good since it's not the nicest thing to get out.

[WagonMan]

Curious as to how much the booster cost? Was there a core charge? TIA, WagonMan

[Kodachrome Wolf]

Curious as to how much the booster cost? Was there a core charge? TIA, WagonMan

I work at a parts store, so I get some rather large discounts on parts. As far as this one went, it was $59.36 plus a $19.00 core charge. FWIW, that's rather close to some of the prices you'll see online (e.g. RockAuto), but I specifically went through work because lifetime warranties are nice.

Regular retail at my location for that one is $89.99 + $19.00 core charge.

[87gtVIC]

Nice work. Amazing how much room it opens up in the bay.


Quite impressed with the photo you got.

[BoulevardRide]

that's real cool you could do that. I hope i never have to do that on mine!