T56 clutch M/C and mounting bracket? [Archive] - Chevelle Tech

: T56 clutch M/C and mounting bracket?


Derek69SS
Mar 23rd, 11, 1:31 PM
My LS1/T56 didn't come with a master cylinder for the clutch, so I'm starting from scratch here, and don't really know where to start. This stuff's all new to me. Something in kit-form would be nice, but I don't want to spend a lot either.

I'm not afraid to modify my firewall for mounting a M/C if it will save me money and/or look cleaner when done. What bore size M/C should I use? (planning to use stock '69 pedal assembly, but willing to modify pedal motion ratios if necessary)

Any suggestions?

Scotch
Mar 23rd, 11, 2:31 PM
Wanna come look at mine?

You can buy or fab a plate to mount the stock LT1 stuff and get it to line up with your new 69 clutch pedal. That should work if the LT1 and LS1 clutch masters are similar, and since they're both T56s, I'd bet they are.

Steve1972
Mar 23rd, 11, 3:29 PM
I've seen a few on LS1 tech that use the stock f-body master set-up. I'll see if I can find them again.

Here's a couple of builds that use an S&P plate that mounts behind the brake booster, they give dimensions for the plate if you want to fab it yourself.

http://www.hotrodlane.cc/Streetstories/68ls1camaro/68ls1camaro1.htm

http://www.hotrodlane.cc/PDFFILES/LS170chevellestoryscreen.pdf

novaderrik
Mar 23rd, 11, 6:05 PM
didn't ATS make a kit just for this that uses a Camaro master cylinder and throwout bearing, with a mounting bracket and instructions on how to modify your pedal?
or was that just for Camaros?

Bad66Chevelle454
Mar 23rd, 11, 7:58 PM
I'd highly suggest to use the stock Chevy set up. That's what I did. Works perfect and you can get parts for it if you're stuck on some road trip. Part number: 12570277. It's cheaper to buy it and ship it from gmpartsdirect than from your local dealer. Comes complete with the master, braided line and reservoir.

For mounting, I used that typical mount, thats kinda like a piece of metal bent on an angle. You can get them from just about anywhere, I got mine from DSE I believe. It puts that master cylinder at the correct angle to match up with your pedal.

Feel free to ask me any questions, I went through all this not too long ago on my car. There's probably even pictures of it in my build thread.

cuisinartvette
Mar 24th, 11, 12:11 AM
Buy the premade bracket, its kind of a complex angle and geometry/throw has to be right or youll blow your slaves out.
had to make mine and figure it out yrs before all these kits came out.

Yoll love the conversion, to date best mod Ive done totally transformed the car.
You can build the motor to be a beast and still cruise the fwy

usc2001gc
Mar 24th, 11, 5:19 AM
If you're going with the stock setup, here's a bracket for $30.00 http://cgi.ebay.com/ebaymotors/LS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-/270715212682?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f07e2538a

andrewb70
Mar 26th, 11, 1:45 PM
If you're going with the stock setup, here's a bracket for $30.00 http://rover.ebay.com/ar/1/711-53200-19255-0/1?mpt=464934337&adtype=1&size=1x1&type=3&campid=5336121898&toolid=10001 http://cgi.ebay.com/ebaymotors/LS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-/270715212682?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f07e2538a (http://rover.ebay.com/rover/1/711-53200-19255-0/1?type=3&campid=5336121898&toolid=10001&mpre=http%3A%2F%2Fcgi.ebay.com%2Febaymotors%2FLS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-%2F270715212682%3Fpt%3DMotors_Car_Truck_Parts_Acce ssories%26hash%3Ditem3f07e2538a)

I don't think that those brackets work well on A-bodies. They were originally designed for 1st gen F-bodies. I recall having a chat with Tyler at ATS and he mentioned some issues when the bracket is used on A-bodies.

I ended up going with the Keisler kit which I am very happy with. The angle was perfect and there are various, inexpensive MCs that are available. I started with the .750" bore MC, but switched to a .700" bore MC to reduce the travel of the TOB. Each setup will be unique of course.

Andrew

BigDawg
Mar 26th, 11, 6:00 PM
I don't think that those brackets work well on A-bodies. They were originally designed for 1st gen F-bodies. I recall having a chat with Tyler at ATS and he mentioned some issues when the bracket is used on A-bodies.

I ended up going with the Keisler kit which I am very happy with. The angle was perfect and there are various, inexpensive MCs that are available. I started with the .750" bore MC, but switched to a .700" bore MC to reduce the travel of the TOB. Each setup will be unique of course.

Andrew

Andrew, I agree with your statement as this bracket does not work well with A body cars. I just purchased this item from the same ebay seller and 1. the mounting holes do not line up and the angle for the mc is not correct. My original thoughts were to simply enlarge the holes, but I think I will just return it and purchase one from ATS or Tick Performance.
Here's a couple of photos of my test fit.
40186

40187

cheveslakr
Mar 26th, 11, 7:19 PM
I don't know about the above pictured bracket but I fabricated my own following a blueprint I posted on another recent thread and it worked out perfect, no issues, on an a-body.


Jerry

Derek69SS
Mar 27th, 11, 12:09 PM
Thanks for all the tips guys!

I'm going to try making my own bracket... probably something welded to the firewall, since everything needs to be repainted anyway. :) I'll use the GM master cylinder, reservoir, and hoses. :thumbsup:

tom_a
Mar 28th, 11, 2:53 AM
I used one from Hurst Driveline
http://i186.photobucket.com/albums/x82/passperf/1HYD1.jpg

Here is a pic installed on a 1970 Chevelle.

http://i186.photobucket.com/albums/x82/passperf/DSC08809.jpg

Bad66Chevelle454
Mar 28th, 11, 12:30 PM
I used that same Ebay bracket and it worked perfectly on my car. Yes, the mounting holes were very tight, but it did go on. After that I just welded a tab onto my clutch pedal, bolted the master to that and I was done.

I just got done installed a 5 speed from Hurst Driveline using the same set-up as pictured above and I didn't like it as much. You have to use the remote reservoir, which doesn't cleanly mount anywhere and how the master mounts with the pedal isn't as nice. With their bracket I couldn't get the angle right to allow the right amount of throw(full throw on pedal but only 1" throw on master). I wasn't impressed with their set up. Truthfully, I'm not impressed with that company, but that's just my personal experience.

Derek69SS
Mar 28th, 11, 1:55 PM
Well now I'm as confused as when I started... ;)

What, if done incorrectly, will cause the slave to blow out? Is it from over-extending the master cylinder? Can't that be adjusted in the linkage to the pedal?

What are you guys using to seal off the firewall? That was one of the reasons I was thinking of making my own bracket, I could just make the firewall come out to the M/C if needed.

tom_a
Mar 28th, 11, 7:07 PM
Derek,

I can't say that I fully understand it either but I believe that your pedal travel can exceed your master thus causing premature failure. I was told you really should want to use the floorboard as your stop instead of a bolt. I really have no idea if mine is correct however the fact that I have actuated several times in the limited drive time and it works. There is some adjustment in the rod I have just as it would be on an aftermarket brake m/c. I noticed Tim (above) mentioned something about only getting 1" of travel so his set up must differ from mine as the Ram TOB I am using only has .700" from start to finish for travel. The spacing for bell housing face to pressure plate fingers need to be measured really good. I had pull the trans to add a shim and flat backing a trans is no fun.

As for sealing the firewall I have not done anything yet. However I am using some one sided sticky joint sealant like below picture arorund the open area of my roll cage bar and floor pan
http://energeticinsulation.files.wordpress.com/2010/12/mbm_weatherstripping.jpg




You have to use the remote reservoir, which doesn't cleanly mount anywhere and how the master mounts with the pedal isn't as nice. With their bracket I couldn't get the angle right to allow the right amount of throw(full throw on pedal but only 1" throw on master). I wasn't impressed with their set up. Truthfully, I'm not impressed with that company, but that's just my personal experience.

I thought most were remote mount reservoir? I understand opinons vary but I thought the bracket from Hurst worked and went on good for me

andrewb70
Mar 28th, 11, 8:20 PM
Well now I'm as confused as when I started... ;)

What, if done incorrectly, will cause the slave to blow out? Is it from over-extending the master cylinder? Can't that be adjusted in the linkage to the pedal?

What are you guys using to seal off the firewall? That was one of the reasons I was thinking of making my own bracket, I could just make the firewall come out to the M/C if needed.

Derek,

You have it exactly right. The main cause for the slave to "blow out" is over extension. Most aftermarket hydraulic TOB do not have a built in travel stop, with the newer Howe bearing being the exception. I am using a Quarter Master TOB and if you look through my build thread you can see what happened as a result of over traveling the bearing. OEM bearing, such as the one you will be using with your LSx/T56 combination, will not have this issue.

The main goal for your setup is to ensure that your pedal geometry will facilitate the full stroke of the stock MC that you are using. Stock LS1 style MCs are 3/4" bore and have a hair over an inch of travel. If your pedal geometry yields less than full travel at the MC, you will experience hard shifting due to insufficient slave travel, which leads to incomplete travel of the clutch spring fingers, which leads to insufficient air gap between the clutch disk and flywheel/pressure plate.

The reason I like my set-up, and the Hurst set-up, is the fact that they use a Gurling style MC (made by Wilwood or Tilton, respectively) that has about 1.4" of effective travel. The pedal geometry is also spot on, so the full travel of the MC can be utilized. This arrangement allows you to manipulate pedal travel, pedal effort, and TOB travel. For instance, as I stated before, I started with a .750" bore MC. This combination gave me a fairly firm pedal and plenty of TOB travel, too much in fact, since I over-traveled my bearing. I really should have had a pedal stop. What I did instead was to get a smaller size MC. This gave me two benefits. It lowered my pedal effort and reduced the TOB travel.

The proper way to check if your TOB is traveling enough to release the clutch is to use a feeler gauge to measure the air-gap between your disk and flywheel/pressure plate. This used to be easy on older setup that had inspection covers at the bottom of the bellhousing. The LS1/T56 bellhousing does not have an inspection cover. What you can do instead is conduct a simple clutch release test. With the engine off and car jacked up and transmission in 4th gear get under the car and start applying a twisting motion to the driveshaft while someone is slowly depressing the clutch pedal. Note the moment that you are able to freely turn the driveshaft by hand and the simultaneous position of the clutch pedal. From that point, you will need another 1"-2" of pedal travel to achieve full release of the clutch. Give or take. So if you find that the clutch pedal is bottomed out and you can still feel drag as you turn the driveshaft, then you know that you need more TOB travel. If you have more than 2" of pedal travel, you run the risk of over-traveling the TOB or the pressure plate. Then you can either get a smaller bore MC or adjust the pedal stop accordingly.

Make sense? :D

Andrew

ed1le
Mar 29th, 11, 1:31 PM
If you're going with the stock setup, here's a bracket for $30.00 http://rover.ebay.com/ar/1/711-53200-19255-0/1?mpt=338864992&adtype=1&size=1x1&type=3&campid=5336121898&toolid=10001 http://cgi.ebay.com/ebaymotors/LS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-/270715212682?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f07e2538a (http://rover.ebay.com/rover/1/711-53200-19255-0/1?type=3&campid=5336121898&toolid=10001&mpre=http%3A%2F%2Fcgi.ebay.com%2Febaymotors%2FLS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-%2F270715212682%3Fpt%3DMotors_Car_Truck_Parts_Acce ssories%26hash%3Ditem3f07e2538a)

I'm using this bracket and although tight, it fit over the studs. I did have to tweak the angle slightly w/ a press to get the slave angle right but it was minor. Hard to beat for $30.

Bad66Chevelle454
Mar 29th, 11, 3:18 PM
I thought most were remote mount reservoir? I understand opinons vary but I thought the bracket from Hurst worked and went on good for me

They are, however in my opinion the stock chevy slave's reservoir is alot smaller and easier to tuck away than the tilton set-up. On my stock chevy reservoir I cut the line and mounted it close to where the wiring comes through on the firewall. When I did the hurst/tilton set up on my buddies car I ended up putting the reservoir off the master cylinder mounting bolt with a little bracket.

Both work, don't get me wrong...just in my experience using both, I felt the stock chevy set up was alot easier and cleaner than the tilton set up.

1sick66
Sep 23rd, 12, 4:19 PM
Sorry to hijack the thread but I have a wilwood master cylinder that mounts straight but needs to be mounted at a 45* angle the only bracket I can find available is this $30.00 eBay bracket but that one does not put my mc at the angle I need. The one pictured above from hurst looks correctly designed but would not put my mc in the correct spot on my 66 chevelle. I tried to call but can't get ahold of anyone. Does anyone know where I can get a bracket that will work?

1sick66
Sep 23rd, 12, 4:34 PM
--------------------------------------------------------------------------------

Sorry to hijack the thread but I have a wilwood master cylinder that mounts straight but needs to be mounted at a 45* angle the only bracket I can find available is this $30.00 eBay bracket but that one does not put my mc at the angle I need. The one pictured above from hurst looks correctly designed but would not put my mc in the correct spot on my 66 chevelle. I tried to call but can't get ahold of anyone. Does anyone know where I can get a bracket that will work?

1sick66
Sep 23rd, 12, 4:40 PM
Sorry to hijack the thread but I have a wilwood master cylinder that mounts straight but needs to be mounted at a 45* angle the only bracket I can find available is this $30.00 eBay bracket but that one does not put my mc at the angle I need. The one pictured above from hurst looks correctly designed but would not put my mc in the correct spot on my 66 chevelle. I tried to call but can't get ahold of anyone. Does anyone know where I can get a bracket that will work?

cheveslakr
Sep 23rd, 12, 5:24 PM
This one??
http://www.ebay.com/itm/LS1-T-56-Conversion-Clutch-Master-Cylinder-Bracket-/280931676385?pt=Motors_Car_Truck_Parts_Accessories&hash=item4168d530e1&vxp=mtr

The ad states "late sixtys to early seventies chevelle" so I'm thinking it's the correct 1 for a 66 too?? It looks like the 1 I fabbed for my 69 and it works perfectly. I'd ask the seller, he seems to know his product.


Jerry