Does the brake booster have dual diaphragms
 

Does a ZR1 brake booster have dual diaphragms?

Thanks

Yes!

'90 & '91 ....

'92+ ..................

Thanks.

Will an LT1 Master cylinder bolt up?

No. LT5 is wider. ZR-1 booster is smaller diameter.

I am not trying to argue.Looking for clarification. GMPartsdirect.com and Eckler's shows the same master cylinder both ZR1 and Base

Peace

Boosters are different


Master Cylinders are the same base vs ZR-1 but has changed through out the years

https://cimg8.ibsrv.net/gimg/www.cor...e448e14645.jpg
So If I drill out the firewall at the 4 points indicated on my picture, a ZR1 booster will fit? If I get a booster for a 94-96 ZR1 my brake pedal rod will be the right length and I will have improved braking. The older boosters rods are a bit short as I understand it. I have ASR also. I can then bolt my master cylinder on. I'm on my 3rd plastic single diaphragm booster. Any reason why this won't work? It would essentially be a proper fit wouldn't it? 1995 and up came with the upgraded brakes less the 13" rear rotors.

Thanks

What 'Improvement' do you expect from the Booster swap?

My old 89 and my 90 ZR-1 were basically the same when it came to braking, only difference was the booster. I am not sure how swapping the booster will improve braking.. I don't recall any pedal feel difference between the 2 boosters either

Swapping the master cylinder or changing calipers would improve braking.

If it were me, I would be looking at Hydra boost units before trying to find a ZR-1 brake booster

I'm trying to avoid replacing this plastic booster again. I don't have a ZR1. I want a proper metal booster for my car and the ZR1 booster seems like it would be a good fit. I don't have power steering.

Thanks

I'm quite confident the issue isn't the mounting point to the 'fire-wall' - that should be the same '92+. I can supply images if you like.**\Booster push-rod should be the same. '92+ is maybe important. Pedal ratio changed I believe in '92.

There's very likely with a much modified car (no PS etc) that an Electric assist could be adapted. There's many. SOME VERY EXPENSIVE SOME LESS EXPENSIVE!

** needs confirmed (seems unlikely maybe)

Thanks for replying. All the pictures I've seen of ZR1 boosters have 4 mounting studs, whereas I only have 2. Am I wrong in assuming they all have 4 mounting holes? Are you saying I can possibly mount it without drilling my firewall? Dave, if you would be generous enough to supply some pictures, that would be so awesome. I located a used ZR1 booster. They are out there. I think I've seen a couple sites with rebuilds available.

I researched the electric power steering a few years ago. The Toyota guys with the easy retrofit pump know what they have. I've contacted a few. I put it on the way back burner. I am pretty used to the manual steering after all these years.

Thanks a million.
You are a wealth of information.

What year is your car? A guess '95! Pedal bracket #6 is the same, ECM bracket #4 is the same for any '92 +. "92 + pedal ratio is different than earlier. I don't know the diameter of the LT1/4 booster shell but all single chamber boosters are larger than doubles. Specific reasons?

Notice that the firewall is pierced right upper and right center in the cutaway!

Search eBay for a 10143544

Here's a link: https://www.ebay.com/itm/C4-Corvette-ECM-PCM-Computer-Mounting-Bracket-10143544-90-96/133032042206?
https://cimg0.ibsrv.net/gimg/www.cor...d37bfdbd94.jpg

https://cimg2.ibsrv.net/gimg/www.cor...9a09796474.jpg

https://cimg5.ibsrv.net/gimg/www.cor...73eabdb5e6.jpg
Yes I have a 1995. What are you implying about the cutouts? Here are pages of my manual. Looks like the same firewall with different holes drilled. Thanks

What I meant to say is "the other 4 holes drilled". The other 4 in my first picture of my car.

The plastic booster is almost 10" in diameter.

Anyone who has removed a booster from any year '90 + when ECM moved to the under-hood location. (I'd maybe be interested in '92+) should be able to confirm that the fire-wall is pierced for both but regardless I believe you see that it's NOT an issue! SPO tends to sometimes not be as specific as the FSM - the FSM is attempting to familiarize you as to what to expect! In your case either 2 nuts or 4 nuts in the cockpit.Regardless already pierced or NOT you've got the ECM bracket o be used as a 'template'.

You need to be sure the ZR-1 booster comes with the pedal push rod and it would be also important to confirm the 'output' push rod is a match. I'd assume so since the master is the same/similar '92+

What year ZR-1 booster have you located?

I see ECM brackets on eBay with 6 bored holes and also some with 4 bored and 2 (lower) slotted as in the FSM and SPO images.Maybe the change is when PCM replaced the ECM. No idea!

I did a quick search of online junkyards and found one for $250 at Corvette Salvage. States it's for 90-95.

Corvette Central has one for $349 https://www.corvettecentral.com/c4-8...2f%3fcount%3d9
I sure would like a discount code for that.

I just had my booster off the other day and replaced it with a used one I got with a bunch of parts. It was freaking hot out. I didn't notice much. Either that booster was faulty (which I suspect since the vacuum valve was missing) or my cam is causing my hard brake pedal. I only have 12" of vacuum at idle. I must say......I used to have good brakes.

Okay. I ordered a booster for a 1995 Corvette from Autozone a few days ago. It's supposed to be at my door tomorrow. My plan is to use this until I get a ZR1 booster. I have a 50/50 shot at them sending me the correct part. I will take pictures of the firewall (bulkhead) when I get the booster off. It's not very difficult to replace if you have a long 3/8" extension and a swivel 13mm. I'm kinda slim anyway, so that helps alot.

Did I tell you it's freaking HOT here?

EDIT: ordered a ZR1 booster tonight

Thanks

https://cimg3.ibsrv.net/gimg/www.cor...ac86f0658c.jpg
https://cimg7.ibsrv.net/gimg/www.cor...719b401e3b.jpg


Looks like I have a template. Thanks.

ZR-1 booster ordered Monday? JY?

Sunday night. ZR1 Corvette it says. 1992-1995. Reman. It hasn't shipped yet, so I am skeptical. It shows a picture of a ZR1 booster.

To talk to a man with the answers, call Matt Sweeting at Power Brake Service, Huntington Beach CA, 714-330-5286, http://PowerBrakeService.net They built a custom dual diaphragm metal booster for me, and the brakes on my '84 will stand the car on its nose!

https://cimg9.ibsrv.net/gimg/www.cor...f57639f22d.jpg

Matt drives a ZR-1 with a HydraBoost power brake conversion.

https://cimg8.ibsrv.net/gimg/www.cor...9a6e8b51a2.jpg

Order refunded!

I'd sure consider the hydraboost as the assist is MUCH better and brake feel is dramatically improved.

I don't have power steering. I can't use hydroboost.

I ended up putting another plastic one on for now. At least it's got a limited lifetime warranty from Autozone.

I actually had Matt in mind when I mentioned 'electric' several posts ago. Since he fabricated the 'dual' for HRR maybe you just have the conversation with him anyway. Several I believe have tried/attempted conversations with him regarding the hydra-boost but I've never seen anyone do a 'start to finish' install on a ZR-1. Other than his personal, I don't recall others. I've seen it discussed only a couple times. I didn't have the Toyota stuff in mind when I mentioned electric.

You should be covered for awhile I'd think with this buy - maybe use your time wisely

A '92+ 'salvage'??????

Matt has a dual diaphragm on his site, ready to buy. $245. http://powerbrakeservice.net/1984-19...te-vacuum.html. It looks like a ZR1 from HRR's picture. That hydro-boost looks like it takes up too much room. What were you thinking in terms of electric power steering? I just bought a MR2 pump off Ebay. I'd lke a booster from a salvage ZR1. But why? Matt has a brand new one for the price I was quoted from a boneyard.

Wouldn't hurt to talk to him The link seems to take a person to a 'dual' intended for a possible install for a car with 'NO' ABS. It shows a hydraulic block BUT then again it's just an image. You need to actually discuss it with Matt or someone else at that facility. You need to talk to 'folks' wild a$$ links to everywhere might get you lots of info!! You've experienced that already it seems. Ask Matt about electric!! There's a couple/actually many I think that have electric here in the vicinity. Many 'well engineered' hot rods

A known 'salvage' should get a person exactly what he pays for. You ask for and pay for a '92+ ZR-1 'dual' that's what you should expect!!

I'm not too worried about it now. I just spend $145 on an Autozone reman. while looking for a salvage ZR1 for at a decent price. Do you have one?
When you talk electric, you are referring to electric steering, correct?

Thanks

No 'electric boost hydraulic' brakes! I had a couple B'villes with Teves and maybe an STE also had Teves. Matt has many. Ain't none inexpensive!

That looks like a lot of extra weight. I'm trying to shed weight although incorporating electric power steering is going to add some weight.

A 'vette friend put electric boost power brakes on his '84, so we have fun comparing cars! I can't match his 409 SBC, but he likes my dual diaphragm brakes better than his electric boost!

He's driving the white Shinoda conversion in this pic, and we're chasing two ZR-1's thru some mountain twisty's! Too much fun!!!

(p.s. I didn't have any trouble keeping up with them!)

https://cimg6.ibsrv.net/gimg/www.cor...24c7399ca2.jpg

:D

Bit late here and you probably have the answer by now, but yes the ZR1 booster will bolt right in if you drill the extra 4 holes right through.

I used to rebuild those plastic PBR boosters here in Australia, a number of Australian cars used them, the replacements you were getting that were constantly failing were either Cardone or AC Delco rebuilds, and they did not use genuine parts to rebuild them. The parts they use are made in China, and they are f***en useless.

I just did one yesterday in an 88 and it had a Cardone in it, the shell was cracked in the rear, and when i pulled it apart to rebuild it i found the diaphragm was pinched in the edge of the booster as they assembled it. It was not screwed together to the correct thickness either. Just plain rubbish. They will fail very quickly if they are not assembled correctly.

As of today, i am not longer able to buy these Genuine PBR boosters new, they have been discontinued, and the rebuild kit was discontinued a few years ago.

The ZR-1 booster is a PBR VH6007, and made in Australia. If it says AC Delco on it then it is NOT an OEM part, it is a remanufactured part, AC Delco never made brake boosters.

I have not yet looked to see what other cars used this booster, but it is not a ZR-1 specific item, it is an off the shelf part GM used at the time.