LS brake swap
#1
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LS brake swap
91 Z28 with drum brakes on the back. I am looking for a pic/template for the mounting bracket for the calipers to the axle mounting flange on the rear brakes. Plenty of info with print out template for the front from Luke Skaff. Thank you for that. But I can't find anything on the rears. Does anyone have a pic of the bracket?
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Car: 1987 Formula (original owner)
Engine: 305 TPI
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Axle/Gears: 9-bolt/3.45
Re: LS brake swap
The only place I know of that offers a drum-to-disc conversion bracket/kit is Ed Miller, but it's for the 3rdgen-style/4thgen LT1-style PBR brakes, not LS1. Here are four pages of brake conversions for 3rdgens. The pictures he displays are all the same for similar types of conversions, so you have to go by the descriptions. I hear he's not easy to reach by email. Ordering seems to be good, just not correspondence. These are products, not templates.
Product Listing (flynbye.com)
Here's the thread he created many years ago for the conversion.
Hassle free drum rear disc conversion to 1LE/ LT1 PBR rear brakes - Third Generation F-Body Message Boards
And here's another thread he created for drum-to-C5/C6. LS1 is similar, but not the same, so maybe he can do one for LS1.
Drum rear to C5/C6 conversion plates done - Third Generation F-Body Message Boards
Product Listing (flynbye.com)
Here's the thread he created many years ago for the conversion.
Hassle free drum rear disc conversion to 1LE/ LT1 PBR rear brakes - Third Generation F-Body Message Boards
And here's another thread he created for drum-to-C5/C6. LS1 is similar, but not the same, so maybe he can do one for LS1.
Drum rear to C5/C6 conversion plates done - Third Generation F-Body Message Boards
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Re: LS brake swap
For the rear brakes the stock LS1 backing plate is used. Just need to locate and drill 4 holes in the axles brake mounting flange. And, with drum brakes cut the wheel cylinder riser off.
The stock LS1 backing plate also provides the mounting and so on for the drum style parking brake. So it really needs to be used.
RBob.
The stock LS1 backing plate also provides the mounting and so on for the drum style parking brake. So it really needs to be used.
RBob.
#5
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Re: LS brake swap
So which parking brake cable do you use on a 91 with the LS rear brake swap. It doesn't look the 91 cables will work with the LS but it also doesn't look the the LS cables will work on the 91 body.
#6
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Re: LS brake swap
Hawks Motorsports has the right cables for the parking brakes. I got a set on my 91 with my MWC 9 with LS rear brakes. I just need to figure out how to tighten up the cable on the inside of the car
#7
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Re: LS brake swap
I've never played with LS1 rear brakes... but wouldn't you just use the 4th gen F-body cables and brackets that screw to the axle? I have a set of 4th gen F-body brackets that I've squirreled away for over a decade thinking I might need it some day if I want to change to internal parking brake shoe.
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#8
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Re: LS brake swap
I've never played with LS1 rear brakes... but wouldn't you just use the 4th gen F-body cables and brackets that screw to the axle? I have a set of 4th gen F-body brackets that I've squirreled away for over a decade thinking I might need it some day if I want to change to internal parking brake shoe.
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Re: LS brake swap
So what's the magic combo? Late 3rd gen cables with 4th gen brackets?
#10
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Re: LS brake swap
It looks like the easiest is to buy Hawks cable, 3rd gen for LS swap. But there was a question about adjustment.???
https://www.hawksmotorsports.com/82-...e-cables-pair/
I have LS backing plate and parts on the way. https://www.ebay.com/itm/363969712820
I plan on adapting (welding) my 91 parking brake cable lever "hook" on to the LS parking brake lever (sorry don't know what to call it). So I can use the 91 cable. I may have to modify the cable mounting bracket. I will have pics and a write up.
https://www.hawksmotorsports.com/82-...e-cables-pair/
I have LS backing plate and parts on the way. https://www.ebay.com/itm/363969712820
I plan on adapting (welding) my 91 parking brake cable lever "hook" on to the LS parking brake lever (sorry don't know what to call it). So I can use the 91 cable. I may have to modify the cable mounting bracket. I will have pics and a write up.
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1989karr (12-23-2022)
#11
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Re: LS brake swap
It looks like the easiest is to buy Hawks cable, 3rd gen for LS swap. But there was a question about adjustment.???
https://www.hawksmotorsports.com/82-...e-cables-pair/
I have LS backing plate and parts on the way. https://www.ebay.com/itm/363969712820
I plan on adapting (welding) my 91 parking brake cable lever "hook" on to the LS parking brake lever (sorry don't know what to call it). So I can use the 91 cable. I may have to modify the cable mounting bracket. I will have pics and a write up.
https://www.hawksmotorsports.com/82-...e-cables-pair/
I have LS backing plate and parts on the way. https://www.ebay.com/itm/363969712820
I plan on adapting (welding) my 91 parking brake cable lever "hook" on to the LS parking brake lever (sorry don't know what to call it). So I can use the 91 cable. I may have to modify the cable mounting bracket. I will have pics and a write up.
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Re: LS brake swap
Hold on, wait a minute..... People have been doing this swap for 20 years and Hawks probably learned from this forum what cables to use.
I'm not interested in "buy from Hawks", I'm more interested in where that cable comes from so the knowledge isn't lost.
I'm not interested in "buy from Hawks", I'm more interested in where that cable comes from so the knowledge isn't lost.
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rurnt88 (11-28-2022)
#13
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Re: LS brake swap
When I installed a 4th gen 98' "LS" brake rear I also installed the body cable bracket from a 4th gen and used the original 4th gen LS brake cables. The bracket I'm referring to is welded to the body & that connects to the single E-brake handle cable and the 2 caliper cables. This was a LONG time ago; but if memory serves I trimmed the "tail" off the 4th gen bracket and left the existing E-Brake bracket in place to hold the original 84 E-Brake handle cable; then connected the 4th gen e-Brake caliper cable to the 4th gen bracket. Adjustment was as easy as turning the adjustment wheel on the LS set-up.
4th gen rears are an 1" longer on each side than the Thirdgen rear, but this only means that running the LS cables under the car a different / best way possible might be needed if using a 3rd gen rear and LS brakes.
4th gen rears are an 1" longer on each side than the Thirdgen rear, but this only means that running the LS cables under the car a different / best way possible might be needed if using a 3rd gen rear and LS brakes.
#14
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Re: LS brake swap
Here's another option from Flynbye. He makes custom cables with adjusters on the ends. I've currently got most of my interior out of my car I might go down and see if there's an adjuster screw on the handle agent itself
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Re: LS brake swap
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Re: LS brake swap
Is there enough exposed free length to cut the cable shorter and swage a new ferrule on the end?
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Re: LS brake swap
The cables almost seemed too short. Were a real pain to install and took up a lot of the spring in the system. I had other brake issues at the time and eventually removed the paring brakes all together (I had an adjuster shear off into the rotor, don't ask me how). I have read you can just use an LS1 cable and widen out the opening on the brake end. There are a few of them on rock auto I will experiment with. They are all under $20 so its worth a shot. My 1990 brake lever does not have any form of adjustment on it. Rather, it has the spring that I had to extend to get enough length. Another $200 lesson down the drain on my car.
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Re: LS brake swap
I've never seen it so can't envision. I'll have to refer back to this thread later if I ever get parts in my hands.
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1989karr (12-19-2022)
#20
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#21
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Re: LS brake swap
I got the flange cut & holes drilled. I cut it by the machined step which looks good on the backing plate. Waiting on parts. Here is the difference between the E cable ends, the 91 on top & the LS 98-02 below.
I sure wish someone that has done the swap would speak up on what they did on hooking up the E brake cable or did you not hook up the E brakes.
I sure wish someone that has done the swap would speak up on what they did on hooking up the E brake cable or did you not hook up the E brakes.
#22
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Re: LS brake swap
I cut the 91 E brake lever at white line. & welded it to a piece of steel & I was going to drill and bolt that to the LS E brake lever but that is HARD so I welded those together.
If you don't have a welder maybe you could sandwich the LS lever between two pieces of steel and bolt it together?
I used the OEM left brake cable & used a left OEM cable on the right side also. The 91 right side is to short. I was having trouble getting the right E brake to release so I added a spring and that works good.
I also added a cable support for the right side to help keep the cable off of the exhaust pipe. You may not need to.
The E brakes work good. The car is still on blocks so no road test. I rebuilt the rear brake calipers and pushed the pistons in my hand. Gravity bleed the brakes but the calipers don't seem to work . Will look into that tomorrow.
If you don't have a welder maybe you could sandwich the LS lever between two pieces of steel and bolt it together?
I used the OEM left brake cable & used a left OEM cable on the right side also. The 91 right side is to short. I was having trouble getting the right E brake to release so I added a spring and that works good.
I also added a cable support for the right side to help keep the cable off of the exhaust pipe. You may not need to.
The E brakes work good. The car is still on blocks so no road test. I rebuilt the rear brake calipers and pushed the pistons in my hand. Gravity bleed the brakes but the calipers don't seem to work . Will look into that tomorrow.
#23
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Re: LS brake swap
I bleed the rear brakes and they work fine. On to the front brakes.
I used the template provided by LukeSkaff.com (thank you) for the front mounting bracket for the caliper bracket mount. I cut mine by the blue line, to lazy to cut on the line. I had to releave the inside corner a little to clear the spindle. If you stay close to the line you won't have any problem. I had to recut the lower lug on the spindle to clear the caliper. I left to much by the green line. Tip: mount the LS bracket on the caliper bracket first and check clearance then mount it on the spindle and use as a guide to cut the spindle. Check clearance.
One of the caliper brackets made contact to the LS bracket mounting bolt so I had to give it some clearance, minor issue but something you need to check. Other than that it went good. I took it for a ride. What a difference. You stop faster with a lot less pressure on the brake pedal. The E brake holds good too. I didn't have any issues with the calipers lining up with the rotors. I bought hubs from BigBrakeUpgrade.com I emailed them 3pm Friday afternoon, They got back with me in 15 minutes and said it would be 2-3 days to ship. Everything is made to order. So I placed the order then. I received the parts Monday morning. WOW. EXCELLENT. All total came to $990 for front & rear swap.
I used the template provided by LukeSkaff.com (thank you) for the front mounting bracket for the caliper bracket mount. I cut mine by the blue line, to lazy to cut on the line. I had to releave the inside corner a little to clear the spindle. If you stay close to the line you won't have any problem. I had to recut the lower lug on the spindle to clear the caliper. I left to much by the green line. Tip: mount the LS bracket on the caliper bracket first and check clearance then mount it on the spindle and use as a guide to cut the spindle. Check clearance.
One of the caliper brackets made contact to the LS bracket mounting bolt so I had to give it some clearance, minor issue but something you need to check. Other than that it went good. I took it for a ride. What a difference. You stop faster with a lot less pressure on the brake pedal. The E brake holds good too. I didn't have any issues with the calipers lining up with the rotors. I bought hubs from BigBrakeUpgrade.com I emailed them 3pm Friday afternoon, They got back with me in 15 minutes and said it would be 2-3 days to ship. Everything is made to order. So I placed the order then. I received the parts Monday morning. WOW. EXCELLENT. All total came to $990 for front & rear swap.
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1989karr (12-23-2022)
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Re: LS brake swap
For the rear brakes, did you swap to a front disc / rear disc prop valve? or did you use the stock disc / drum valve?
I heard people have been using the stock disc / drum valve and it works better than upgrading to the disc / disc valve but im not too sure about that...
I heard people have been using the stock disc / drum valve and it works better than upgrading to the disc / disc valve but im not too sure about that...
#25
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Re: LS brake swap
For the rear brakes, did you swap to a front disc / rear disc prop valve? or did you use the stock disc / drum valve?
I heard people have been using the stock disc / drum valve and it works better than upgrading to the disc / disc valve but im not too sure about that...
I heard people have been using the stock disc / drum valve and it works better than upgrading to the disc / disc valve but im not too sure about that...
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1989karr (12-23-2022)
#26
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Re: LS brake swap
great to know!! The price of a dic dic valve is so high... but I heard that they dont work hat well so Ill probably try the stock disc / drum first.
Any other input is appreciated as well!
#27
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Re: LS brake swap
Even though I took drums off my 91, the RPO #'s say it had disc originally. I think someone swapped my complete rear end. I did not change my prop valve. My brakes work great.
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1989karr (12-23-2022)
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