I thought I would post up some pictures I have of the early and later 1LE front brakes. I have a 1988 A4U that came factory with 1LE front brakes. And I have a 1989 1LE Camaro which had the "production" version of the 1LE brakes. The differences are interesting. I'll post up other series of information I learn from going through the car. Perhaps shed light on the myths of 1LE. :-)

For now ... front Brakes are the topics.

First. Here is a picture of the 1LE brakes off the 1988 car:



I did not know at the time I had Corvette calipers. I thought they were the same. But they are not. Below compares the LARGER 1LE calipers with the corvette. Also the corvette banjo connector is on the side vs. the 1LE is on the bottom! So be aware if you are making up 1LE ... you need the FBODY specific calipers.



Now to an interesting observation. The caliper carrier bracket in 1988 was a pre-production part. No part numbers. Some grinding marks to make it fit. In 1989, it was a production part. The 1988 part is on the LEFT. The 1989 part is on the RIGHT:

Overall the 1988 part is thinner in many areas compared to 1989.



Notice the 1989 part is thicker between the bolts compared to the 1988 part. As well the 1988 part has more material on the outer edges.



Now lets look at the attaching point to the spindle.

This is the 1988.



This is the 1989. The 1988 one was ground to fit. The 1989 was cast with the clearance.




Now the attaching plate. In 1988 it was smooth. In 1989 it had the "dots" protruding out to keep the carrier from moving.






I'll have other info to post as I go through the car.

Cheers!
Mark.

 

Interesting! Thanks for posting.

 

Cool

 

Wasn't there a difference in the corvette caliper size when the HD 13" brakes were introduced over the standard 12"?

 

Subd

 

I have not personally compared, but I understand there was. The C4HD which is the 13" rotor was the same thickness as the F-body 1LE rotor. HOWEVER, the 1LE calipers have the banjo bolt attaching to the bottom END of the caliper. The C4 ones has it attaching to the SIDE. Now there could have been CDHD with the bottom mount ... I can't confirm. You'd think GM would use the same ones for cost.





Mark.

 

I used corvette 13" HD calipers and rotors when doing the conversion. Even though the banjo bolt does indeed attach in a different spot compared to the 1LE caliper, my stock brake lines still worked. I did have to grind ever so slightly on the banjo bolt for clearance, but it works.

 

I knew about the banjo bolt placement and I'm fairly sure the calipers are setup as a universal casting so they can't be used on either side until they are machined. Even then, a plug and some quick machine work could move it to the other side if needed.

 

Great stuff, thanks Mark.

 

So am I reading this right - the 1LE Camaro caliper was larger than the PBR Corvette one and not the same part number?

 

The 1LE caliper was larger than the base corvette caliper, Not the corvette HD caliper but still different part numbers.

 

The 1LE mystique continues to grow.

 

The bolt spacing that attached the caliper to the 1LE spindle bracket was unique. So they were not the same part. Certainly they were adapted from the vette one. The early 1988 part is probably closer to the vette one, and the 1989 one is more production F-body. I could not find a decent picture of the vette caliper brackets for comparison.

Mark.

 

Cool stuff!

This is not to argue, but to learn...

Why the differences for some components? Do these actually do anything performance-wise? Were the minor differences between the C4, C4HD and 1LE calipers a calculated, engineering decision? Or was it just something that happened due to parts suppliers?

 

The 1LE calipers were specific to the F-body cars. They were adapted from the vette calipers (which were wide enough for the F-body rotor) and machined for F-body (location of banjo connector).

I doubt there are any differences in performance from the standard vette, C4HD, and 1LE as they all have the same piston size same hose size, and driven by similar master cylinders.

The rotor size and thickness would be a difference. The thicker, the better the heat is dissipated. The larger diameter of the C4HD 13" has more surface area (granted you need larger wheels too).

The 1LE came from the Player's series that started in 1986. Teams would run through the corners when the brakes got hot. In short order GM made up a 12" kit consisting of Caprice rotors, a specially cast Brembo caliper, and an adapter. These lasted for two seasons after which the 1LE caliper became production as it was already DOT certified where as the Brembo was not (and probably cheaper since it was already in the parts bin0.

Mark.

 

Thanks again for another great history lesson Mark! Did you mean '89? Can't wait to read about the rear disks!

 

Nope. The 89's have more meat in the sense are thicker blocks of steel. The 88's are scalloped in various areas, not as big of castings. The 88's look adapted from another mold perhaps where as the 89's look correct for the spindle.

Mark.

 

Here is a picture of my 1LE brakes before and after. The goal was preservation, not restoration. Keeping things as original as possible was key ... but also keeping things safe for driving.

You can see what I started with was an set from a car that sat for decades in storage. And someone thought gold paint was a good idea. The gold paint cleaned up really well and revealed the caliper carrier color which is a dark grey metallic of sorts. The dust shield actually has green paint from the factory during assembly (both sides show). The rotor was in poor shape and not correct for 1989), so I packed that away and replaced with a genuine 1LE casting 18016211 with a fresh resurface. All that was left is a new hose - and I have to say the routing is very tight.



Also notable was a marking on the factory spindle and notice the dust shield hole is not tapped:





Mark.

 

I'm not a huge fan of how the factory ran the hose for the 1LE calipers, plus they are a little different for each side. (have 2-3 sets of 89 1LEs and have worked on many TTAs. I kind of like the corvette location for the hose mounting, wish they would have used that setup.

 

Some new info on 1LE casting numbers.

The catalog part number for the rotors is 18006211.

My 1988 1LE brakes used rotor 14008647.
My 1989 1LE brakes also used 14008647.

The original stories from GM were that the 1LE cars used the 12 rotors from a Caprice. The casting number 14008647 was a stock part in a C10, which is also the big bolt pattern 12" rotor.

When I rebuilt the brakes on the 89, I used a set of 18006211 rotors thinking that was the correct part. But lack of research ... turns out the car had it's original rotors on it! So ... I'll have to get those turned and keep with the car for the purest who wants that.

The more I look at this 89 ... it has most of it's original parts intact.

Mark.

 

So besides the part# difference, are the rotors the same?

And are you saying the original 1LE rotors were the same # as the C10 rotor, despite having a different wheel bolt pattern spacing?

 

What it appears is that GM used the stock C10 casting as the base for the machining of the 1LE parts. I can only go what I find on the casting numbers. Perhaps the Caprice also used the same part? I'd have to find some originals to know for sure.

More to the mystery of how the 1LE came to be.

 

I have some 89 1LE rotors, I'll check the casting numbers when I get a chance.

 

The 1LE rotor was definitely machined on the C10/Caprice rotor casting. It does make sense the casting refers back to the C10 in parts listings because that was the 1973 origin versus the 1979 Caprice starting point for those rotors.

The '73-'87 light duty C10 rotor is effectively a '79-up HD brakes Caprice rotor. They used the same A6 & A3 bearing sets as well. The '77-'78 A-body, F-body, & B-body used different bearing sets than '79-up.

Original rotors you fellows research should support this. Replacement rotors lacking casting nos. obviously will not.

 

To avoid the potential for confusion, I'd like to point out that there were two different C10 rotors used. Starting in '81 (pretty certain) there was a standard light duty rotor and an optional heavy duty rotor. The light duty rotor is only one inch thick. The heavy duty rotor was the same as used since '73.

 

Very cool. One more fact about origin of 1LE rotors now confirmed.

 

An update (plus I fixed the picture links!).

So ... I brought home my 1988 A4U race car to work on (After many many years). First thing was to put back on the 1988 A4U brakes. Back in that time, racing 1LE brakes were tough to come by and teams hoarded parts. When my 88 was done racing, the brakes were kept and stock crap put on. Here we have the stock stuff put on back in 1990 era. Sitting for many years. Below is the one year only 1988 1LE prototype brakes used on A4U cars, and below that is the production 1LE parts.



The brake rotor for the A4U is the 14008647 part number, not the 1LE number.

Now for fun ... here is early 1LE setup. This was from a GM cutaway car, a 1987 Camaro. The brake rotors are the 6211, but an early version of it. I had not pulled these apart to check what version of carrier it used .. 88 or 89. Curious too ... the struts are hand numbered 1989 1LE (and R7U) parts. The numbers are made with a punch and dot matrix numbers. The production 1LE had the usual stamps.







Now ... the project was simply to put back the original 1988 parts on to a 1988 car. (and some clean up of mud and muck - the car has been stored from 1990-1999, and again from 2002-2017).

The carrier bracket in 1988 had a different design. There is a flat "ear" part that fits between the rotor and spindle:











The 1988 part WILL NOT fit the 1989-up spindles. While a challenge to see, the ear part will not clear. A different angle cut on the spindle.



Soooo ... the 1988 is the one year unicorn of 1LE parts. While nifty and neato ... tough to work with.

Here is something else I discovered. The 1LE rotor is thicker than a stock rotor as where the wheel mounts:




It's about 1/2" ... so really you don't need the front/rear offset rims on a 1LE car ... you can run all REAR to tuck in, or all Front to stick out. My 1989 1LE looks the same ... but I never took notice.

Anyways ... more info on 1988, 1989 1LE stuff. For that purest who wants to make the concourse restoration!

Mark.

 

Very cool details! Thank you Mark!

 

cool indeed

 

A cool pic showed up in another post by z28cop. Quite relevant to the history of 1LE brakes.

Now in the first version of the heavy duty brakes, GM had already been working on adapting the larger Caprice/C10 front brake rotor onto the F-body (same spindle side). Due to the racing program and teams sliding through corners due to failing brakes, GM fast tracked this program and in TWO WEEKS made up the 12" rotor upgrades for the Player's race cars.

In this pic, you can see how much this was a parts program ... the caprice/C10 rotor was taken, studs knocked out, and new holes re-drilled.




The Calipers are Brembo and the pads are unique to this setup.

From what I have seen, the re-drilled rotors were used in 86 and into 87. The factory small bolt circle 12" rotors came out in late 87 (I have no evidence on when).

Then into 88, the brakes became more of a production item. The Brembo's got pulled due to not having DOT approval, and the Vette's HD calipers did. There's more to the story I'm sure ... but in a nutshell.

Anyways ... really cool pic from October 1986.

Mark.

 

That's a question I wondered about, why the early cars had brembos then the pbrs. The non DOT cert makes sense.

 

I can't recall where I read that, or heard that. Talked with lots of folks over the years, it may have been Phillip Minch I spoke with (now I am straining to remember). Trying to get the Brenbo's DOT was more effort that retrofitting the already DOT PBR Vette HD calipers.

Still an expensive bit of fabrication work to A. modify stock spindles and B. design and cast a new bracket adapter for a rather limited run of cars. The Vette calipers are also unique as they are drilled different than F-body.

Ya just brakes as some say ... but lots of work to get them there.

Mark.

 

Not to bring up a old thread but to add some 1LE info i hadn't seen. Stumbled on this today.
(if we need to move this or start a new thread let me know!

https://www.motortrend.com/features/...982-1420-98-1/

 

Great find, very detailed! Too bad the photos are not in color. I didn't realize (or maybe forgot) GM used the same master cylinder for 1LE option as they did for cars with rear drums. Has any one ever actually confirmed that only 1LE cars got the gas tank baffles, I thought this was often debated?

 

I didn't realize the tank volume changed at the same time as the revision to the baffle.

 

The 1LE subject is filled with lots of myths and lore, old wives tales and BS.

1LE was a nice package of stuff in the early cars but as time went on and we got closer to the last 3rd gens in 1992 it became less and less of a performance package because many of the parts became standard on high performance Camaros and Firebirds. The G92 Camaros and the equivalent Firebirds had most of the stuff in the 1LE package as the years went on. In the later years 1LE was basically a big front brakes, aluminum driveshaft, and a few higher durometer bushings in the suspension. Some of the later 1LE Firebirds got the pencil brace and Wonder Bar from the IROC/Z28 but many of the Firebirds got the pencil brace anyways.

Ain't no 18 gallon gas tank with a crazy swinging fuel hanger sucking the last few drops of gas out the tank. It's the same 15.5 gallon tank with a little baffle and a better fuel sock/strainer. Lots of 89 car got the same 1LE gas tank setup and all 90+ 3rd gens even V6 cars got it.

 

It didn't, this was a somewhat early press release, and it does contain some bad info, 18-gal tank, and swinging pickup never happened for production.

 

It is an early article as the abutment brackets are 1988 only versions. These are the same one on the 88 players cars. In 89 they were revised to have better clearance to the spindles. I suspect the photos were early engineering stuff. The adapter bracket is shiney (would have been the anodized gold color). They did not have the dimples on it that came on in 1988. And the two bolts were different sizes!

The fuel tank photo is a great example showing the high wall reservoir and pickup. Although from inside the tank it looks more significant.

Back in 88/89, these were the tricks for road racing ... much before any aftermarket setups were available. Lots of ideas today came as a result of the adapter bracket idea from 1LE.

Mark.

 

In 89, only the 1LE cars got the revised tank. In 1990, any port injection should have had it. Racing led to better production parts. You can read the parts books and see the change over in numbers to backup my claim.

G92 and 1LE were seperate parts. 1LE was the package of the HD brakes, struts, shocks, bushings, and in early years, the fuel tank, and sway bars (36mm on either camaro or TA, and wonderbar on both).

Funny to read the fuel tank capacity ... the root of where the myth started back in the day. I know GM advertized it as a longer range tank, but it was really only in a corner.

Great article and great photos!

Mark.

 

The EAR part which is next to the large bolts bolt makes this a 1988 only part. the rounded EAR was removed in later castings. In 88, the parts were ground to fit (on my 88 players cars). 89 were a finer casting, more production like.

 

And the production version for comparison:

 

1988 Players brakes (same as magazine)

 

And the dimples .. 1988 none, 1989 yes. Lots of changes from pre-production 1988 1LE parts to production 1989 parts.

 

My 2 89 350 cars, non 1LE, 4,000 apart in vin numbers, the early car didn't have the sump in tank, the later one did/does. (They both do now.) I can only assume that between there is when the sump tanks started to become production items.

I was hoping you'd pickup on those very early photos, just didn't know which 1LE thread to post it..

 

I had a reply I was typing up last night in which I tagged @TTOP350 because I remember him mentioning in the past he had dropped the tanks in 89 cars and found some that had the high wall reservoir "1LE" tanks installed and some that didn't. I fell asleep before I finished the reply and never posted it.

I too over the years have found some 89 Firebirds with the "1LE" fuel tanks with high wall reservoirs and improved fuel sock/strainers inside them and some that didn't have them. They were all 89 Formulas or GTAs with LB9 5 speed or L98 automatic powertrains with N10 dual cat exhausts. So none of the earlier ones without N10. I have no idea the build dates or VINs now. Have no idea what Camaros or the V6 or TBI cars had in them. 87 to 92 Firebirds are my passion with the 89 Formulas and GTAs being my jam. These were original unmolested 1 or 2 owner cars with 10k to 35k miles with a few being under 50k miles. None were high owner cars that had been through all the local trailer parks with God only knows what had happened to them.

Right now due to be delivered today is a new gas tank for a 89 L98 N10 GTA ASC convertible. It's getting a full fuel system makeover gas cap to throttle body. I'm not doing the work because another project is on the lift right now. Trusted local mechanic that knows these 3rd gens doing it as a side project at his home garage. He called last week after dropping the tank saying a new one was needed due to old gas varnish and pounds of rust inside. I'll see if I can get some pics inside to see if it has a "1LE" high wall reservoir tank.

 

Great read. Thank you.

 

My 89 1LE is one of the first made ... and it had the gas tank with high wall reservoir. Odd the later ones did not. My 89 was a GM Engineering car ... so it might have been special order to resemble the players cars.

Mark.
PS. Great article to find!

 

I'm guessing that my Feb 88 built car is prob the earliest one to get the high baffle tank in it based on everything I've seen and read so far in various threads. I posted internal pics of it in my rebuild thread. At some point I have to pull the front brakes down and go through them and will takes pics and see if they have the dimples or not. I know it left the factory with the pre-production parts but not sure what got swapped out in seasons following.

 

I ordered all the 1LE brake parts from GM about early 1990's or so. I even ordered the correct spindles, rather than cutting up the factory spindles. I do not remember the dimples.. But possibly it's on there. I also did change the prop valve.

 

Did you ever get any pics of the tank?