H55 Stiff Clutch (1 Viewer)

[marshcat]

I just picked up my '87 HJ61! I've never driven a 60-series before, but driving it home the clutch didn't feel quite right. There's no resistance at all on the pedal for the first few inches of travel. And then the lower half of the clutch travel is STIFF. I'm not a weak guy and I really had to stomp on it to move the pedal.

Is this normal? Might the clutch need a bleed?

 

[marshcat]

Doing a bit of reading it seems like my clutch booster might be the culprit

 

[DrRock]

I would definitely perform a bleed first. This will flush out any debris in the system and get you a baseline. Did you check the clutch pedal adjustment too? This is detailed in the FSM. The clutch system contains two major components, the master cylinder up in the firewall and the slave cylinder on the bell housing.

Cheers, James

 

[CruiserTrash]

@marshcat As above, a fluid flush is always good - leastwise it's not going to hurt anything. Just bleed while adding fresh fluid until you have fresh fluid all the way through to the slave cylinder. Honestly both US-spec 60s I've had have a clutch pedal not dissimilar from what you describe. No resistance for 1-2" and then it's fairly stiff when the action finally happens. On both trucks I flushed the fluid and adjusted everything per the FSM. On my current 60 the master, slave, and clutch are new, and the flywheel has been resurfaced.

 

[marshcat]

@marshcat As above, a fluid flush is always good - leastwise it's not going to hurt anything. Just bleed while adding fresh fluid until you have fresh fluid all the way through to the slave cylinder. Honestly both US-spec 60s I've had have a clutch pedal not dissimilar from what you describe. No resistance for 1-2" and then it's fairly stiff when the action finally happens. On both trucks I flushed the fluid and adjusted everything per the FSM. On my current 60 the master, slave, and clutch are new, and the flywheel has been resurfaced.

Have you ever replaced or rebuilt a clutch booster? Here's why I think the clutch booster might be bad:

The clutch pedal stiffness is the exact same with the engine running as with the engine off. Whereas the brake pedal has noticable power assist with the engine running but gets much stiffer if the pedal is pumped with the engine off. Clutch pedal is always the same. I imagine that with the clutch booster functional the pedal effort would be lower with the engine running.

 

[CruiserTrash]

Have you ever replaced or rebuilt a clutch booster? Here's why I think the clutch booster might be bad:

The clutch pedal stiffness is the exact same with the engine running as with the engine off. Whereas the brake pedal has noticable power assist with the engine running but gets much stiffer if the pedal is pumped with the engine off. Clutch pedal is always the same. I imagine that with the clutch booster functional the pedal effort would be lower with the engine running.

Possibly so. 60s don’t have a clutch booster, just master and slave cylinders. This is a difference I was unaware of.

 

[marshcat]

Interesting! Wonder if the clutch booster was only on Euro models. You can see here the brake booster on the left and separate clutch booster on the right

 

[BrickRunner]

View attachment 3701584

Interesting! Wonder if the clutch booster was only on Euro models. You can see here the brake booster on the left and separate clutch booster on the right

From what I've read, the clutch booster is more a diesel thing than a specific market thing. My HJ60 is JDM and has it too.

 

[BrickRunner]

Replacing my clutch booster solved the that issues you also have for me.

 

[marshcat]

From what I've read, the clutch booster is more a diesel thing than a specific market thing. My HJ60 is JDM and has it too.

That makes sense! The diesel clutches would have heavier springs to handle extra torque.

Did you have your OEM booster rebuilt or did you install one of the aftermarket chinese boosters?

 

[BrickRunner]

From Amazon. It's been almost two years with no issues.

 

[AussieHJCruza]

Clutch booster is a market/trim thing. My FJ62 Sahara has a clutch booster.

 

[ceylonfj40nut]

Check if you have good vacuum. HJ60s have a vacuum tank in engine bay. Connect gauge to it to see. Do you have good brakes?

 

[marshcat]

Check if you have good vacuum. HJ60s have a vacuum tank in engine bay. Connect gauge to it to see. Do you have good brakes?

Yeah, brakes feel great. So I assume vacuum is fine.

 

[relaxedcruiser]

Yes, check vacuum supply first. Sounds that your clutch booster is gone or really maladjusted. Maybe try to hook up the brake vac hose just to try. The loose travel at first could also be a bad adjusted booster/master cyl. relation. That pin which transmits the power onto the master cyl. piston needs to have just about zero freeplay while not moving the piston.
When I got mine it had some mm freeplay there and the pedal had no resistance whatsoever during the first five cm/ two inch as a result.
Here are two pages which might be of interest.