Manual hydraulic clutch pedal using factory GM parts

81cutlass

Comic Book Super Hero
Feb 16, 2009
3,524
113
Western MN
Hydraulic clutch parts for G bodies are available but are either expensive or not fully featured.

My goal is to have a pedal that was affordable, using factory parts for ease of replacement and had fully featured parts for the cruise shutoff and startup cutout.

You need
1. early (83-88 ish) manual S10 brake pedal and clutch pedal assy.
2. 3rd gen F body master cylinder
3. Nook and transmission sells a O ring to -4 fitting for the master cheap, mcloed has one for 35 and russel sells a pair for 25 or something.
4. (optional) i used a howe HRE-8287 for the lines
5. (optional) i used a howe HRE-82876 T5 hydro TOB for my t56 with an adapter bushing

The s10 clutch pedal bracket needs to be cut off the S10 brake pedal bracket that bolts from the inside to the booster. Theres 6 rivets a bolt and a few spot welds.


S10 brake pedal bottom, G body top, they are the same length.


S10 clutch pedal ends up in the exact spot as the G body brake pedal, left right, top down, and in out.


The top part facing your left knee when its in the car will get cut off, and I drilled a hole in the firewall part and put a 6mm bolt. I would put a couple more around the pedal to reinforce it. The top main bolt in the S10 clutch pedal bracket gets shared and bolted to the stock G body brake pedal bolt.




For a master, 3/4 3rd gen. I think this was a dorman. I cut off the rod off and found it was threaded, 1/4" coarse. The G body bracket pivot for both pedals is about 2" closer to the firewall so it needs to be cut down.



I welded a nut extender cut in half or so to the master was adjustable. I cut off 2 1/4, id do 2 1/2" shorter next time.


This part is pretty common, use the stock cruise hole and I made a cardstock pattern to mark holes, center punch and drill.



Improvements needed-

More bolts to hold the pedal bracket to the clutch bracket, I only have 2 or so and its a bit loose. I would suggest welding the bolts to the back of the bracket so you wont have to thread the nut on while holding the bolt. I am also missing a support rods that attach the clutch pedal pivot bolt to the firewall, again I gotta take 2" out, I am still working on that, too cold right now. Also the angle of the master is a bit too aggressive so I might have to build a slight angle wedge to make the rod push more directly straight.

My order of ops to install was

1. Remove window wiper motor
2. Remove engine harness firewall connection
3. Remove fuse panel from firewall under the dash
4. Unplug all wires from the pedal bracket and anything in the way
5. Pull any cruise wires out
6. take 1 bolt out that is facing upwards holding the pedal bracket to the dash support
7. Take the 4 nuts holding the booster on out and wiggle the pedal out
8. Drill the clutch pedal bracket off and attach to G body bracket, cut and bend as needed
9. Weld bolts on
10. Remove clutch pedal and bolt brake bracket to car with only 1 nut on top left nearest the VIN plate.
11. Bolt clutch pedal bracket to brake pedal bracket (very tough, get limber!)
12. Bolt remaining pedal bracket nuts back on
13. Repeat 4 through 1 in reverse order
14. Put S10 clutch master resovior hose and -3 or -4 fitting onto 3rd gen master before it goes into car, theres not enough room for later
15. Put master cyl in place and bolt in, bleed system (that was tough, make sure the master is fully extended before you attach the pedal, if the master isnt fully out it wont grab fluid on return stroke
16. Make sure the pedal fully disengages the clutch without going too far, if it goes way to far the pressure will spike and you run into high pressure and blow the seals.
 
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Reactions: 3 users

oldsmobile joe

Royal Smart Person
Nov 12, 2015
1,755
113
mpls
nice write up. thanks
 
  • Agree
Reactions: 1 users

1evilregal

Comic Book Super Hero
Apr 23, 2009
2,993
113
Greensboro, NC
after all the transmission trouble I've had with the GP, I've been re-thinking the Regal's set-up, and if I go manual, this'll be a great help! thanks for doing the write up!
 

Bar50

Royal Smart Person
Jan 1, 2009
1,150
113
Tulsa, OK
Great intel.

Will it clear headers? Big block Chevy headers? I remember someone (GSI) offering a custom clutch pedal that was similar to get the correct geometry.
 

marcar1993

G-Body Guru
Aug 31, 2007
692
43
New Jersey
These setups should clear any headers, the master tucks up under the brake booster, and its small. Then route the line wherever you want.
My friend has a manual in his malibu, and the first incarnation was an nv3500 with a modified s10 pedal/master setup. It had a funky release and no pedal travel. When he pulled that trans to go t56, he used my John Bzdel pedal as a template to modify his s10 pedal, and switched to a 3/4 gen f body master. Much better setup now.
I'm curious to see how your setup feels when you start using the car, especially with that really short pedal rod, which would mean the rod is bolted to the pedal pretty low, no? Far from the pivot point, meaning less leverage. The John B pedal is often ragged on for the stiff pedal, and that mounts higher with a stock length master rod.
 

pontiacgp

blank
Mar 31, 2006
29,389
113
Kitchener, Ontario
I used an F body clutch pedal and used the bolt and bushings from the F body pedal set up with the G body pedal housing. I cut the F body clutch pedal arm and added 3/4" to it's length. Measured the position of the pin for the master putting the pedal at the position I wanted and welded a tab with the pin. Cut the G body brake foot pad the to the size that is in a stick car. One thing I missed was not putting a doubler on the fire wall where the master is installed. I could only use one stiffening rod from the F body set up on the right side and the firewall eventually cracked which caused the rod on the master clutch cylinder to snap.
 

Bar50

Royal Smart Person
Jan 1, 2009
1,150
113
Tulsa, OK


Well, this is what I was trying to avoid.
 

81cutlass

Comic Book Super Hero
Thread starter
Feb 16, 2009
3,524
113
Western MN
Yeah I havnt drove it much but the pedal seems pretty easy so far. I was bleeding it and using my arm and although it was tough to push I was able to. The 4th gen master feels very nice and I get full stroke. Engagement is a bit low but that might just be a little more bleeding and my misalignment of the TOB.

I also have the problem that I can only use 1 reinforcement rod. There just isnt much room in the G body with the fuse panel so close.
 

pontiacgp

blank
Mar 31, 2006
29,389
113
Kitchener, Ontario
Yeah I havnt drove it much but the pedal seems pretty easy so far. I was bleeding it and using my arm and although it was tough to push I was able to. The 4th gen master feels very nice and I get full stroke. Engagement is a bit low but that might just be a little more bleeding and my misalignment of the TOB.

I also have the problem that I can only use 1 reinforcement rod. There just isnt much room in the G body with the fuse panel so close.

no need to bleed the clutch, the reservoir sits higher then the master so fill up the reservoir and grab a beer while the air makes it out of the reservoir. I pump the pedal a few times and never had any left in the system. I could only use on rod as well and after a couple of years the firewall cracked and the master broke. I made a doubler and used a large washer to spread the pressure on the left side that had no reinforcement rod. .
 

81cutlass

Comic Book Super Hero
Thread starter
Feb 16, 2009
3,524
113
Western MN
no need to bleed the clutch, the reservoir sits higher then the master so fill up the reservoir and grab a beer while the air makes it out of the reservoir. I pump the pedal a few times and never had any left in the system. I could only use on rod as well and after a couple of years the firewall cracked and the master broke. I made a doubler and used a large washer to spread the pressure on the left side that had no reinforcement rod. .

I could not get mine to bleed. My problem is the bleeder on these Howe TOB's is at the 2 oclock position and the feed line is at 3 oclock or so. I had to manually turn the TOB so the bleeder was roughly at 1230 and manually pump the pedal to bleed it. Not any fun!

Also found out the master has to be fully extended for it to "grab" fluid from the resovior. Mine was like an 1/8" compressed and wouldnt flow.

Live and learn! :)
 
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