JMC HYDRAULIC CLUTCH QUESTIONS

67P51 · Aug 29, 2007

I need some feedback on the JMC hydraulic clutch system. I currently have a 67 with 351C and Tremec TKO with a Mcleod scattershield. I have broken two clutch cables in the past year. It is now set up with the "Mustang Steve" cable conversion.
Any opinions on the JMC install? The car has the factory power disc brake booster and I am a bit concerned about clearance on the firewall.
What about the scattershield, any mods needed? The JMC website mentions the late model bellhousing for most kits.

Any help is appreciated.

rbohm · Aug 29, 2007

before you spend something like $600 on a hydraulic system, check with dazecars website and see if it is possible that his brackets can either be adapted to your trans, or if he has a bracket you can use. i bought his T5 hydraulic clutch bracket, and the workmanship is great. who knows, you might even talk him into using your trans for a prototype, and getting the first unit for free. daze? what do you think?

red65 · Aug 30, 2007

The JMC kit has worked well for me for the past ~3 years, including a fair amount of track time. It's on the pricey side, to be sure, but the installation was straight forward, part quality is good, and customer support from JMC was top-notch. I don't know if it'll clear a power brake booster (who needs power brakes?)

VTStang66 · Aug 30, 2007

I have the JMC system on my car and I think it's garbage. Besides the fact that it's damn near impossible to bleed, it has an inherent design flaw so that even when it's bled completely and everything is working perfectly, the slave cylinder doesn't have enough motion to completely engage/disengage the clutch. I had to choose between having the clutch not disengage all the way, or tightening the freeplay adjustment way down so that it would disengage completely when I hit the pedal. Of course that way it was riding hard on the throwout bearing all the time, and wore it out. I'll never recommend the JMC hydraulic kit. I'm redoing the car now and I'll definitely be going with something else. Maybe it's just my combo, but it just didn't work on my car.

Centerforce II 11" clutch, tremec 3550 trans. I don't think the moment was too long on the clutch arm because it barely stuck out of the scattershield. I actually had to cut the scattershield a bit to use the hydraulic slave on there. Either their master needs to be bigger, or the slave needs to be smaller.

One more thing: If you do use the JMC system, MAKE SURE you remember to ground your engine. Mine was grounding through the clutch cable and it blew 2 of them when it sparked on the firewall. Very annoying problem.

CraigMBA · Aug 30, 2007

67P51 said:
I need some feedback on the JMC hydraulic clutch system. I currently have a 67 with 351C and Tremec TKO with a Mcleod scattershield. I have broken two clutch cables in the past year. It is now set up with the "Mustang Steve" cable conversion.
Any opinions on the JMC install? The car has the factory power disc brake booster and I am a bit concerned about clearance on the firewall.
What about the scattershield, any mods needed? The JMC website mentions the late model bellhousing for most kits.

Any help is appreciated.

Where did the cable break?

Was the pedal travel always easy, or did it 'bind up' right before the cable broke?

I have customer who has a similar setup to yours and had problems with the TO bearing hanging up on the adaptor between the scattershield and the trans (he has a t-56, but I think the adaptor is the same. It would bind up on the adaptor and "POP"..........

70dvr · Aug 30, 2007

I have the JMC set up. Late model bell housing, Centerforce dual friction clutch and Tremec 3550. 28,000 mile's and no problems. It was a pain to bleed though.

10secgoal · Aug 30, 2007

VTStang66 said:
I have the JMC system on my car and I think it's garbage. Besides the fact that it's damn near impossible to bleed, it has an inherent design flaw so that even when it's bled completely and everything is working perfectly, the slave cylinder doesn't have enough motion to completely engage/disengage the clutch.

Who did you buy the JMC kit from ? I'm curious. I've never had a problem until recently when they were out of stock. I tried a knock off and it had the same problem. Come to find out the knock off has a bore size that is too small which is the reason it doesn't work.....maybe you think you have a JMC ? Not to knock your intelligence, but they look identical. They even have dust boots on them that say CNC, even though CNC doesn't make them.

P51, it'll fit your booster as long as you don't have some odd ball pancake booster.
65-66 have the problems with the power boosters. They say you can't run them, but there is one I know of that fits.

68EFIvert · Aug 30, 2007

When I installed my JMC kit I bled it before I installed it on the tranny. Everyting else was installed so it was only the slave cylinder that wan not bolted down. I did not have any problems bleeding it that way. I don't have much time behind the wheel of the car yet so I can't give you an good idea of how it works but for the little I have (driving in and out of the garage to body shop/exhaust shop) it worked fine.

67P51 · Aug 30, 2007

My cables broke about 2/3 of the way down to the scattersield. the first time it was obvious that it had been getting pretty hot from the exhaust pipe/manifold. The outer sheath was partially melted. Second time aroud I wrapped it in that aluminized heat tape and slid some Aeroquip silicone fire sleeve up the lower 2 feet. Second cable shows no sighns of heat damage. I tried to route it as best I could, but it is pretty tight with the manifold and power steering ram cylinder. I am using the stock exhaust manifolds. I've been thinking of going to a set of Sanderson headers, but I need more info on those before I pull everything apart. The engine bay is pretty packed and I don't look forward to the swap.

Both times the pedal was pretty stiff, but smooth. It was just the last few drives before this last break that I felt it getting funny. Seemed to smooth out after a few cyles.

jcode68 · Aug 30, 2007

I am using the JMC unit with T5 trans, FR clutch/pp and factory late model bell housing. I love it! No problems once I got it properly bled and I don't have any problems with clutch not disengaging. I am running Hooker Comp long tubes and have plenty of space with zero interferance. The cost weas $400, but I'll bet you are already past that with 2 cable failures, not to mention your time. Am running mine with power brakes also and as long as you have the factory booster, you should not have a problem. Lastly, the tech support was great as well. They definately are knowledgable about our classic stangs and understand service. You can click the link in my Sig and view some pictures of my install on my CarDomain page.

mustangdave · Aug 31, 2007

If your worried about clearance, I saw they have a remote reservoir that I assume you could mount anywhere?

VTStang66 · Aug 31, 2007

I don't remember who I got it from, not JMC, but it came in a JMC box with JMC instructions. Another thing that bothered me about it was that to bleed it I had to run brake fluid out all over my long tube headers and it ate the coating off.

Not to thread-jack, but is anybody running a hydraulic t/o bearing?

CraigMBA · Aug 31, 2007

That cable shouldn't break in the middle. That's the strongest part.

Have you checked your ground strap lately? That's the wire from the engine block to the chassis. If you are missing one or its in poor shape it'll use the cable for a ground until you melt it in two.

I used to see Camaros with auto trans cables that would break the same way. They would work for a while, and then get real stiff, and then break. This would usually go on 2 or 3 times - untill the parts guy would open the hood and point "where's your ground strap". Those were the good old days when parts guys knew something..

garner67 · Aug 31, 2007

Hydraulic TO bearing

VTStang66 said:
I don't remember who I got it from, not JMC, but it came in a JMC box with JMC instructions. Another thing that bothered me about it was that to bleed it I had to run brake fluid out all over my long tube headers and it ate the coating off.

Not to thread-jack, but is anybody running a hydraulic t/o bearing?

Yep, I just installed a McLeod TO bearing, and it works great. Bleeding was simple, but I used a Mityvac, which may have simplified process.

Here are links to both the bearing and Mityvac:
http://www.mcleodind.com/product_guide.html
http://www.mityvac.com/pages/products_bcbe.asp

JMC HYDRAULIC CLUTCH QUESTIONS

67P51

New Member

rbohm

red65

Member

VTStang66

CraigMBA

New Member

70dvr

New Member

10secgoal

Active Member

68EFIvert

Member

67P51

New Member

jcode68

Active Member

mustangdave

My rearend needs a stud and two nuts.

VTStang66

CraigMBA

New Member

garner67

New Member

Similar threads

JMC HYDRAULIC CLUTCH QUESTIONS

New Member

Member

New Member

New Member

Active Member

Member

New Member

Active Member

My rearend needs a stud and two nuts.

New Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency