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Does the brake booster have dual diaphragms

 
Old 06-29-2019, 01:39 AM
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Default Does the brake booster have dual diaphragms

Does a ZR1 brake booster have dual diaphragms?

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Old 06-29-2019, 07:51 AM
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Originally Posted by A95Y View Post
Does a ZR1 brake booster have dual diaphragms?

Thanks

Yes!

'90 & '91 ....

'92+ ..................
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Old 06-29-2019, 12:11 PM
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Thanks.

Will an LT1 Master cylinder bolt up?
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Old 06-29-2019, 01:13 PM
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Originally Posted by A95Y View Post
Thanks.

Will an LT1 Master cylinder bolt up?
No. LT5 is wider. ZR-1 booster is smaller diameter.
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Old 06-29-2019, 02:44 PM
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Originally Posted by secondchance View Post
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
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Old 06-29-2019, 03:42 PM
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Originally Posted by A95Y View Post
Does a ZR1 brake booster have dual diaphragms?

Thanks
Boosters are different

Originally Posted by A95Y View Post
I am not trying to argue.Looking for clarification. GMPartsdirect.com and Eckler's shows the same master cylinder both ZR1 and Base

Peace

Master Cylinders are the same base vs ZR-1 but has changed through out the years
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Old 06-29-2019, 04:37 PM
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Originally Posted by -=Jeff=- View Post
Boosters are different




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

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Old 06-29-2019, 04:42 PM
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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
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Old 06-29-2019, 04:56 PM
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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

Last edited by A95Y; 06-29-2019 at 04:59 PM. Reason: Thanks
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Old 06-29-2019, 10:15 PM
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Originally Posted by A95Y View Post
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)

Last edited by WVZR-1; 06-30-2019 at 06:17 AM.
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Old 06-29-2019, 11:20 PM
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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.

Last edited by A95Y; 06-29-2019 at 11:21 PM. Reason: studs
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Old 06-29-2019, 11:32 PM
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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?

Last edited by WVZR-1; 06-29-2019 at 11:56 PM.
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Old 06-30-2019, 01:18 AM
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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

Last edited by A95Y; 06-30-2019 at 01:19 AM. Reason: Thanks
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Old 06-30-2019, 01:53 AM
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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.
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Old 06-30-2019, 04:51 AM
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Originally Posted by A95Y View Post
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!

Last edited by WVZR-1; 06-30-2019 at 04:58 AM.
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Old 06-30-2019, 11:37 AM
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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.
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Old 06-30-2019, 09:32 PM
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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

Last edited by A95Y; 07-01-2019 at 01:03 AM. Reason: EDIT
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Old 07-01-2019, 03:49 PM
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Looks like I have a template. Thanks.
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Old 07-01-2019, 04:33 PM
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ZR-1 booster ordered Monday? JY?
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Old 07-01-2019, 04:46 PM
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Originally Posted by WVZR-1 View Post
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.

Last edited by A95Y; 07-01-2019 at 04:49 PM. Reason: more
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