Rear Right Brake Caliper from GM on back order on first generation REGAL’s without sport suspensions.

[89-W-Body-Regal]

Hi, I’m looking for a w body’s expertise here.

I need to replace my rear right caliper on my 1989 Buick regal custom coupe. I always got ACDELCO calipers because I was happy with the oem quality they always brought me. I never really liked the store brand labels. I always went with oem gm parts. 

So I went on Rockauto where I always buy my calipers from and found out they don’t have the one in stock for the rear right with acdelco but they do for the rear left. I also found out they have one for the rear right in acdelco but only with sport suspension. I always got the calipers without sport suspension because I have the base model with not many options so I know I don’t have sport suspension.
 

I went on gmparts.com to see if they had them still for the rear right to make sure it wasn’t discontinued. I’ve seen two different part numbers matching the rear right. I saw for the rear left there is only one part number. I’ve noticed for the rear right there is two part numbers. I’ve tried to order the part number without sport suspension from two dealerships online and they said it was on back ordered and will not be available for who knows. I found out a local Cadillac dealer in my area had one in stock. They told me the same thing. This part is on back order. I asked why does the official gmparts site say they are in stock? He said you will not find any in stock even if gm tells you the dealership has one available because they never change their part listings because there are so many part numbers on back order so it’s hard to manage.
 

It’s just strange I never noticed it before because they always had my part available. All online they are all out of stock besides gm dealer parts sites. Why would they back order the one without sport suspension and keep the one with sport suspension? I would like to know what is the difference between the calipers without sport suspension and the calipers with sport suspension? Is sport suspension the leaf spring option? I learned on this forum the factory put leaf spring codes stamp on the leaf springs and to make sure the option is equipped the code can be found on the service parts label on the spare tire cover.

 

The calipers look completely interchangeable from their photos. Is there different threads for the brake hose banjo bolts maybe or designed differently? I wouldn’t want to guess or try using the other caliper with sport suspension if they are designed with different suspension options. GM has different part numbers for a reason unless they become interchangeable. I know a website where I can find out if part numbers were discontinued or replaced. And the site didn’t mention these part numbers can be interchangeable.

What other brands do you recommend to use? Keep in mind, I recently bought the autozone store brand after I found out they back ordered ac Delco. It was bad out of the box so I went to the store today for my money back.

 

Parts below for without sport suspension and with sport suspension. 

 

GM Part # 19141030

ACDelco Part # 18FR781

THIS PART FITS VEHICLES WITH APPLICATIONS OUTLINED BELOW:

• w/o Sport Suspension

GM Part # 19141010

ACDelco Part # 18FR761
 

THIS PART FITS VEHICLES WITH APPLICATIONS OUTLINED BELOW:

• FE3 Sport Suspension

Edited December 3 by 89-W-Body-Regal

[Schurkey]

What is the most-likely difference between calipers for sport suspension vs. normal suspension?  Piston diameter?

[55trucker]

On 12/3/2024 at 6:22 PM, 89-W-Body-Regal said:

Parts below for without sport suspension and with sport suspension. 

 

GM Part # 19141030

ACDelco Part # 18FR781

THIS PART FITS VEHICLES WITH APPLICATIONS OUTLINED BELOW:

• w/o Sport Suspension

 

GM Part # 19141010

ACDelco Part # 18FR761
 

THIS PART FITS VEHICLES WITH APPLICATIONS OUTLINED BELOW:

• FE3 Sport Suspension

I honestly believe that you're *overthinking* this situation.

these 2 are found on Amazon, the *781* is priced $8 more than the *761*.

They cosmetically appear to be identical except for *what I see* the park return lever being a *new* item on the *761* vs a *used reman* item on the *781*, there were no piston dia changes '88 thru'93.

As for ACDELCO themselves, I don't feel that they will supply you with an item that will outlast another rebuilders product & much of what ACDELCO supplies comes from Asia or possibly Mexico, I personally lean towards Cardone for my *reman* items. They are American.

This leads me to my next question....what has happened to the current caliper other than a piston seizing up or a fluid leak that you feel it is necessary to replace it?

 

Edited December 5 by 55trucker

[White93z34]

I've legitimately never heard of any difference between the horrid 88-93 calipers.

[rich_e777]

Nugeon(BBBInd) seems to be the only people restoring the right side calipers and are based out of Alabama since 1987. Same caliper numbers for a TGP.

[Schurkey]

On 12/5/2024 at 2:13 PM, White93z34 said:

I've legitimately never heard of any difference between the horrid 88-93 calipers.

Ehhhh...They get a lot of bad publicity, but I haven't had any problem with them on my two cars.

The big-deal with brakes on the first-gen cars is more due to the vacuum boosters, in my experience.

It does help to actually USE the park brake frequently.

[White93z34]

They are absolute trash. Perhaps in less corrosion prone areas of the world they last better... not sure what part you're from.

Yeah the vacuum boosters are junk. It was you who brought the issue to my attention... since I replaced the one in my Z34 its never stopped better.

I can only beat stuck slide pins out of the housing so many times. I tried the parking brake thing helped but never really fixed the issue. I'm quite happy that you've never really had the amount of issues with them that most people have had.

Since I've changed to the 96' redesign calipers I've had about one failure total over the years.

Got to the point where I just banked on replacing them yearly whenever they inevitably got locked up and ruined a set of pads/rotors. Back in the day Autozone was really regretting that lifetime warranty

[Amanita]

1 hour ago, White93z34 said:

They are absolute trash. Perhaps in less corrosion prone areas of the world they last better... not sure what part you're from.

Yeah the vacuum boosters are junk. It was you who brought the issue to my attention... since I replaced the one in my Z34 its never stopped better.

I can only beat stuck slide pins out of the housing so many times. I tried the parking brake thing helped but never really fixed the issue. I'm quite happy that you've never really had the amount of issues with them that most people have had.

Since I've changed to the 96' redesign calipers I've had about one failure total over the years.

Got to the point where I just banked on replacing them yearly whenever they inevitably got locked up and ruined a set of pads/rotors. Back in the day Autozone was really regretting that lifetime warranty

Today I learned that '96 cars have a different caliper design than the prior years.

[White93z34]

well technically it started in 1994 on everything except lumina, with notable exceptions of the 95+ lumina/MC reverting back to drum for awhile on base models (should give you an idea of how confident gm was in their old calipers )

and then went as late as 1997 on the cutlass that was kept on the gen1 platform and was it 98? or 99? when the 1.5 gen lumina/MC was discontinued. where it starts is kinda odd and where it ends is kinda fuzzy.

[89-W-Body-Regal]

On 12/5/2024 at 1:57 PM, 55trucker said:

I honestly believe that you're *overthinking* this situation.

these 2 are found on Amazon, the *781* is priced $8 more than the *761*.

They cosmetically appear to be identical except for *what I see* the park return lever being a *new* item on the *761* vs a *used reman* item on the *781*, there were no piston dia changes '88 thru'93.

As for ACDELCO themselves, I don't feel that they will supply you with an item that will outlast another rebuilders product & much of what ACDELCO supplies comes from Asia or possibly Mexico, I personally lean towards Cardone for my *reman* items. They are American.

This leads me to my next question....what has happened to the current caliper other than a piston seizing up or a fluid leak that you feel it is necessary to replace it?

 

Like other people said below, depending on the part you’re from it will get rusty and it seized the piston. Dirt and corrosion made the seal leak internally. I went with autozone because of the limited lifetime warranty and got a bad caliper out of the box. I sent that back and was able to find ac Delco and it was a lot better. I was just wondering why it’s hard to find the part number without the sport suspension and if they were a difference between the two. 

[55trucker]

3 hours ago, 89-W-Body-Regal said:

Like other people said below, depending on the part you’re from it will get rusty and it seized the piston. Dirt and corrosion made the seal leak internally.

Do not blame the caliper for this situation, this particular design is a high maintenance design. Remember to constantly use the parking brake, keep the calipers clean, do not allow dirt buildup in between the parking brake lever & the caliper housing.

Pull the calipers at least once a year & inspect them, ensure the sliders are moving freely.

Seeing as the piston is an internal item & is protected by an external dirt shield they do not usually seize because of external dirt or corrosion, but they will seize due to lack of maintenance, where the brake fluid has not been flushed on a regular basis. Keep this in mind...brake fluid is hygroscopic, that means it attracts moisture, moisture gets into the caliper bore, works on all of the metal parts, flush the fluid & do it regularly.  

I can't speak for anyone else but I still have 30 year old calipers on my car, they are kept painted & clean, even tho the car sees very limited use nothing gets neglected.

[89-W-Body-Regal]

19 hours ago, 55trucker said:

Do not blame the caliper for this situation, this particular design is a high maintenance design. Remember to constantly use the parking brake, keep the calipers clean, do not allow dirt buildup in between the parking brake lever & the caliper housing.

Pull the calipers at least once a year & inspect them, ensure the sliders are moving freely.

Seeing as the piston is an internal item & is protected by an external dirt shield they do not usually seize because of external dirt or corrosion, but they will seize due to lack of maintenance, where the brake fluid has not been flushed on a regular basis. Keep this in mind...brake fluid is hygroscopic, that means it attracts moisture, moisture gets into the caliper bore, works on all of the metal parts, flush the fluid & do it regularly.  

I can't speak for anyone else but I still have 30 year old calipers on my car, they are kept painted & clean, even tho the car sees very limited use nothing gets neglected.

How often do you recommend bleeding? Once a year?

[55trucker]

My rule of thumb is every 36 months, that will depend on where in the country you live, if you live in a higher humidity region flush the system more often.

All brake fluid (glycol) with the exception of silcone based fluid is hygroscopic. Keeping the system clean is something that is generally overlooked by most vehicle owners.

When you purchase replacement brake fluid & you open the container (or containers) to use it try to use most of if not all of what's in the container. Leaving a capped partially used unsealed container on the shelf is just as bad as what will happen to what's in the cars system. Humidity knows no bounds.