Clutch Pedal Return Movement

The Era of The Square Body Racing Comets
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jarudd74
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Clutch Pedal Return Movement

Post by jarudd74 »

My car has a cable type clutch actuation system. Yesterday I noticed that the pedal was not returning to its fully disengaged position after use. Thus, the clutch was not fully engaged, and it slipped when I pressed the gas pedal. By "lifting" the pedal with my left foot, the clutch fully engaged, and all was well with acceleration.

I am unfamiliar with the cable type actuation system. I looked under the dash and did not see any spring attached to the clutch pedal that would return it to its unengaged position. That suggests to me that the pedal return is provided elsewhere in the system. But where? Do I have some binding in the system? Will a spot of lubrication resolve my issue? If so, at which points? Or do I have a bigger problem, perhaps within the clutch. I have not looked at the actuation mechanism from under the car.

Thanks in advance for any information or advice.
Jerry
1965 Caliente 302 T5
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poboyjo65
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Re: Clutch Pedal Return Movement

Post by poboyjo65 »

should be down on the clutch fork,from fork to lower part of the shock tower near the frame motor mounts (if towers haven't been cut out). there is a hole & slot for the spring. the hook of the spring goes in the slot & the point of the hook sticks back out the hole. fork with have a hole for the hook on the other end.

the big one that should be under the dash is designed to help push the pedal down for less leg fatigue. they probably didn't need it for that type clutch.

slot & hole;
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Johno

Lou's Comet
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Re: Clutch Pedal Return Movement

Post by Lou's Comet »

poboyjo65 wrote:
Fri Jan 06, 2023 8:04 pm
should be down on the clutch fork,from fork to lower part of the shock tower near the frame motor mounts (if towers haven't been cut out). there is a hole & slot for the spring. the hook of the spring goes in the slot & the point of the hook sticks back out the hole. fork with have a hole for the hook on the other end.

the big one that should be under the dash is designed to help push the pedal down for less leg fatigue. they probably didn't need it for that type clutch.

slot & hole;
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With a cable type wouldn't the clutch fork be pulled instead of pushed? And if so wouldn't the spring need to go the other way?

I have no experience with the cable type and was just thinking it would be opposite.

Boss has a cable type. I think.....

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poboyjo65
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Re: Clutch Pedal Return Movement

Post by poboyjo65 »

Lou's Comet wrote:
Fri Jan 06, 2023 8:08 pm
poboyjo65 wrote:
Fri Jan 06, 2023 8:04 pm
should be down on the clutch fork,from fork to lower part of the shock tower near the frame motor mounts (if towers haven't been cut out). there is a hole & slot for the spring. the hook of the spring goes in the slot & the point of the hook sticks back out the hole. fork with have a hole for the hook on the other end.

the big one that should be under the dash is designed to help push the pedal down for less leg fatigue. they probably didn't need it for that type clutch.
With a cable type wouldn't the clutch fork be pulled instead of pushed? And if so wouldn't the spring need to go the other way?

I have no experience with the cable type and was just thinking it would be opposite.

Boss has a cable type. I think.....
Probably right Lou. I didnt even think about that . I know I've seen some go backwards,the cable part ,so it pulls the fork instead of pushing . I just figured the spring would have to go same way as stock? :? we need Larry the cable guy! :)
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Johno

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Re: Clutch Pedal Return Movement

Post by A/FX »

I have never seen a return spring attached to the Z bar that connects to the chassis or shock tower, there is a return spring on the lower link of the Z bar but it goes to the clutch fork, basically it holds the clutch rod tight to the clutch fork. ( retracting spring in the diagram)
Or am I missing something ?
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‘64 Cyclone/ Boss 302,quads,4spd, Winters 9”

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poboyjo65
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Re: Clutch Pedal Return Movement

Post by poboyjo65 »

Who said Z bar? :?
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Johno

A/FX
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Re: Clutch Pedal Return Movement

Post by A/FX »

poboyjo65 wrote:
Fri Jan 06, 2023 10:23 pm
Who said Z bar? :?
I misunderstood the explanation. I reread it. The retracting spring does not seem strong enough to return the pedal to the stop. But I could be wrong….
‘64 Cyclone/ Boss 302,quads,4spd, Winters 9”

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Boss/Cyclone
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Re: Clutch Pedal Return Movement

Post by Boss/Cyclone »

I have cable clutch in my 65. Sounds like it is out of adjustment. Do you have an adjustment at the firewall? You can see mine above the master cylinder in this picture. There is a sleve behind the cable that screw in or out. Also, a threaded part of the cable at the clutch fork for extra adjustment.

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1965 Mercury Cyclone former drag car, 1971 Boss 351 engine, 4 speed, ladder bars, etc. Now returned to a street car.
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Larry

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Boss/Cyclone
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Re: Clutch Pedal Return Movement

Post by Boss/Cyclone »

Another common issue that causes your symptoms can be a melted clutch cable. It can stretch when hot and need replacing.
1965 Mercury Cyclone former drag car, 1971 Boss 351 engine, 4 speed, ladder bars, etc. Now returned to a street car.
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Larry

jarudd74
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Re: Clutch Pedal Return Movement

Post by jarudd74 »

Thanks for the information and advice. My cable passes under the support bar and then down to the clutch, passing close to the header (less than an inch). So, I suspect that an overheated cable might be the source of the binding. That being written, I did find a replacement cable kit from MDL that is designed for a 65 Comet. The instructions call for routing the cable past the oil filter and then along the block. The kit includes a bracket that uses one of the oil pan bolts for mounting. But MDL also notes that their kit might not work with some headers because of the proximity of the cable to the header. My headers are Tri-Y design.

Did you have any header proximity routing issues with your installation? If so, how did you resolve those issues?

Thanks again for any information and advice that you have for me.
Jerry
1965 Caliente 302 T5
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Boss/Cyclone
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Re: Clutch Pedal Return Movement

Post by Boss/Cyclone »

I used a heat shielding sleeve from DEI. Can't remember the exact size but something like the one in I linked below. Also used a ceramic disc from Maximum motorsports because I run a blow proof bellhousing and it also gets pretty hot. Did this 7 years ago, no issues since.



Heat sheild.
https://www.ebay.com/itm/332899786592?c ... 25d29658fa


ceramic disc
https://www.maximummotorsports.com/Clut ... -P504.aspx
1965 Mercury Cyclone former drag car, 1971 Boss 351 engine, 4 speed, ladder bars, etc. Now returned to a street car.
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Larry

jarudd74
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Re: Clutch Pedal Return Movement

Post by jarudd74 »

Do you recall the name of the vendor from whom you bought the cable conversion kit? The firewall penetration for the cable setup in your car is similar to my configuration. However, the two vendors that I have found, MDL and Scott Drake, offer conversion kits that penetrate the firewall much closer to the brake master cylinder. I would like to use the current firewall penetration rather than cut a new one.

Thanks.
Jerry
1965 Caliente 302 T5
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Boss/Cyclone
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Re: Clutch Pedal Return Movement

Post by Boss/Cyclone »

Mustang steve. It was long ago, seems they cost a bit more now.
https://mustangsteve.com/product/clutch ... l-ck165-p/

I had to make one modification. Added a few inches to the bellhousing to make up for the firewall being closer to the pedal in a 65 Comet than a Mustang.

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1965 Mercury Cyclone former drag car, 1971 Boss 351 engine, 4 speed, ladder bars, etc. Now returned to a street car.
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Larry

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