Clutch Master Cylinder Replacement

[andrewbr]

Mine decided it doesn't want to hold in fluid anymore, I have a replacement on order that hopefully fits. I'm trying to form a plan of action before taking anything apart and have two questions:

1. How do I get the pin out that attaches the cylinder pushrod to the pedal? I don't see anything obvious holding it in, but I was in the "TVR service position" in the footwell so it's possible I missed something.
2. How do I get the bottom bolt on the master cylinder out??? And then presumably back in again without dropping it into the depths of the body/fender.

Thanks

[MikeE]

Try undoing the master cylinder retaining nuts from inside the footwell, if you’re lucky the bolts won’t spin. If not you’ll need someone else to hold the bolt steady from the access point in the engine bay.

The clevis pin looks like this, so you un clip it from the shaft then pull the pin out of the pedal. When you do check the condition of the clevis pin as they can go oval over time, if so replace it as they’re cheap.

https://partsfortvrs.com/tvr-parts/part-details/tv...

[andrewbr]

That picture of the clevis pin explains it perfectly, thanks.

[nzflash]

I did this recently. The hardest bit I found was opening the clevis pin clip. The rest was ok.

Undo and remove clevis pin.
Remove fluid from cylinder with syringe
Undo pipe union from cylinder. The pipe may be reluctant to come out due to the swaged end. It will come out with a jiggle.
Remove mounting bolts.

If you drop anything down the access panel when removing the bolts don't panic. You should be able to remove it from the footwell behind the pedal box plate.

I chose to remove my seat to give easier access to footwell. Only takes a couple of minutes to remove.

Good luck!

[Jon100p]

easiest way to release the clevis pin clip is to use an adjustable spanner on the arm part (between pin and clip) to rotate it on the pin axis and pop the clip open.

[citizen smith]

nzflash said:

I did this recently. The hardest bit I found was opening the clevis pin clip. The rest was ok.

Undo and remove clevis pin.
Remove fluid from cylinder with syringe
Undo pipe union from cylinder. The pipe may be reluctant to come out due to the swaged end. It will come out with a jiggle.
Remove mounting bolts.

If you drop anything down the access panel when removing the bolts don't panic. You should be able to remove it from the footwell behind the pedal box plate.

I chose to remove my seat to give easier access to footwell. Only takes a couple of minutes to remove.

Good luck!

For a bit more extra room, remove the steering wheel as well.

[andrewbr]

Thanks all for the help and suggestions.

Friend and I tackled this job today, wasn't too bad with a helper, took us maybe 2.5 hours. All suggestions above are definitely helpful - remove steering wheel for better access, remove nuts from the footwell while your helper holds the bolt heads in place from the engine bay side.

The worst part was removing the clevis pin on the pedal, mine was stuck pretty good. Some heat and pliers helped (be careful of your carpet). This took more time than removing the actual master cylinder itself.

I used a TRW brand master cylinder for a Triumph TR6, part number PMC133. The cylinder itself fit well (including the thread for the outlet connection - 7/16 x 20 for reference) but I did have to swap the actuator rod over from my old master cyl - carefully remove the main rubber seal and remove circlip holding the rod in.

My pedal is still quite soft however, we bled it and the fluid looked good but there must still be air in the system somewhere. Will probably bring it somewhere for a pressure bleed.

[MikeE]

Glad you got it sorted and my top was helpful!

If you don’t mind, where did you source the master cyclinder and what was the cost?

[andrewbr]

I'm in the USA and bought it from British Parts Northwest

https://www.bpnorthwest.com/clutch-master-cylinder...