BJ74 Clutch adjustment/freeplay (1 Viewer)

[Malahki]

I have a 1989 JDM BJ74 with about 20K on a new clutch. I have always thought the clutch engages to close to the floor and has too much freeplay on top.

When starting off the pedal is only about 1/2" off the floor when it starts to grab and is fully engaged with several inches of pedal travel remaining at the top of the pedal.

I have always went with 1 to 1 1/2 inches of free play at the top of the pedal on other vehicles, which typically meant a couple of inches of travel at the bottom of the pedal before engagement.

Should I adjust this clutch? Do I need to lengthen or shorten the shaft between the clutch booster and master cylinder?

 

[earl]

Definitely pull the master off. You should immediately know if the push rod is putting pressure on the master. Very quick and easy adjustment at least on my BJ70. Also check your pedal free play. You don't want it putting any pressure on your master cylinder.

If the booster push rod is out of adjustment, then you'll be looking at shortening it by using the adjusting nut.

 

[Malahki]

What is the desired amount of free play travel at the top of the pedal stroke?

 

[kbushnz]

Have a read of this post. I threw up a page from a manual with the adjustment specs

https://forum.ih8mud.com/70-series-tech/392923-strange-clutch-issues-pics.html

 

[Malahki]

The pedal height and free play on the clutch booster were in spec but the push rod was no where near touching the master cylinder when the pedal was fully raised. I lengthened the push rod until their was only a still a slight gap and now the clutch is engaging in an acceptable range of travel. Thanks Guys

 

[Malahki]

So after adjustment I thought everything was fine but I noticed the pedal starting grabbing real low again. Then I discovered if I pumped the pedal a few times it would grab in the desired position again. Does this indicate a problem with my clutch master cylinder? Or is it my clutch booster? it is not leaking air and the pedal is not stiff at all.

 

[Radd Cruisers]

So after adjustment I thought everything was fine but I noticed the pedal starting grabbing real low again. Then I discovered if I pumped the pedal a few times it would grab in the desired position again. Does this indicate a problem with my clutch master cylinder? Or is it my clutch booster? it is not leaking air and the pedal is not stiff at all.

Air or the cylinders are dying... time to bleed or replace.

~john

 

[Malahki]

Air or the cylinders are dying... time to bleed or replace.

~john

So I guess you are saying it could be either the Master or slave cylinder. Sure hope its not the master as last time I looked they were not available for the RHD BJ74.

Of course its not the booster because I have a brand new one of those sitting on the shelf

 

[Hulsty]

Sure hope its not the master as last time I looked they were not available for the RHD BJ74.

I bought one only a couple of months back, brand new AISIN from South Australia.

 

[Malahki]

Thanks Hustly, I found one as well. It is for the non turbo BJ70/73 and the only difference is the whole where the heat shield bolts to the front is not threaded.