Clutch Master Cylinder

[gb_brown]

Hi All,

Has anyone had problems with Wilwood master clutch cylinders from PNM? I replaced the original Lotus one my car about 18 months ago (only done about 2500 miles since if that) and now it's slowly leaking and not holding any pressure. I can't see where it's leaking from and have checked to make sure everything is tight. After re-filling and bleeding the system it doesn't hold any pressure, the clutch pedal never has any weight to it. The other thing I noticed when bleeding the system is that the clutch fluid was being discoloured to a metal\grey colour after a few pushes of the clutch pedal.

I've put the original master cylinder back on, though can't test it as I also have a PNM S\S clutch cable and don't have the correct adapter for the original Lotus master cylinder. I need the same one as used on the slave cylinder.

The clutch fluid discoloration looks exactly the same colour as the grease on the pushrod, so I'm assuming a seal has failed and is introducing air\loss of pressure to the system and causing the leak?

Cheers

Gareth

[lrg_machine]

Hi All,

Has anyone had problems with Wilwood master clutch cylinders from PNM? I replaced the original Lotus one my car about 18 months ago (only done about 2500 miles since if that) and now it's slowly leaking and not holding any pressure. I can't see where it's leaking from and have checked to make sure everything is tight. After re-filling and bleeding the system it doesn't hold any pressure, the clutch pedal never has any weight to it. The other thing I noticed when bleeding the system is that the clutch fluid was being discoloured to a metal\grey colour after a few pushes of the clutch pedal.

I've put the original master cylinder back on, though can't test it as I also have a PNM S\S clutch cable and don't have the correct adapter for the original Lotus master cylinder. I need the same one as used on the slave cylinder.

The clutch fluid discoloration looks exactly the same colour as the grease on the pushrod, so I'm assuming a seal has failed and is introducing air\loss of pressure to the system and causing the leak?

Cheers

Gareth

Gareth

That's EXACTLY what happened to mine at the Oxford meet.

I too had a PNM master cylinder about 18 months old ( though I'd done probably 8 - 10K )

Bought another one from SJ this time. Maybe anyone else with a PNM version that's about 18 months old should have a good look.

[gb_brown]

Hi Jeremy,

I was at the Oxford meet when that unfortunately happened to you, I was the guy with the tools and it does seem to be exactly the same problem as you had. I've just been lucky in that it happened in my garage!

I'll phone PNM tomorrow to see if anyone else has reported the same problem and if they got a dodgy batch from Wilwood.

Cheers

Gareth

[Kato]

Talk to Pete at PNM and find out what's happening. It's unlikely it's down to PNM, more likely to be a faulty batch from Willwood. LEW's SE has one and haven't had any problems yet, but it's not really done the mileage. Which version do you have?

LEW has the 0.700

[CarlC]

Thanks for the tip off Gareth.

I have the PNM/Wilwood Master on mine and its been on for about 12 months now so Ill do an inspection of the fluid and the unit to see if i can see any leaks. Cant say I've noticed any problems with the clutch as yet but Ill check it out anyway.

[gb_brown]

I've just spoken to PNM and it sounds like Jeremy and I are not the only ones to have had this problem! Probably was a dodgy batch, but might be worth checking yours if you've got one. Mine was fine the last time I used it, then a week later the clutch pedal went straight to the floor and there was a puddle in the bonnet.

I'm going to send mine back to PNM who are going to fit a seal replacement kit, I assume for free. If I hear anything else, I'll post an update.

Gareth

[lrg_machine]

I've just spoken to PNM and it sounds like Jeremy and I are not the only ones to have had this problem! Probably was a dodgy batch, but might be worth checking yours if you've got one. Mine was fine the last time I used it, then a week later the clutch pedal went straight to the floor and there was a puddle in the bonnet.

I'm going to send mine back to PNM who are going to fit a seal replacement kit, I assume for free. If I hear anything else, I'll post an update.

Gareth

Let me know how it goes and I'll send mine back as well. then I'll have a spare.

[rydning]

I have a wilwood too with larger bore than the stock one.I bought it from rally design several years ago (3?) and it have worked fine.

But I also have some metal/gray fluid,I have flushed the system earlier....Hmm... I realy got suspicious of the quality of this product now.

[lrg_machine]

I have a wilwood too with larger bore than the stock one.I bought it from rally design several years ago (3?) and it have worked fine.

But I also have some metal/gray fluid,I have flushed the system earlier....Hmm... I realy got suspicious of the quality of this product now.

Mentioning the colour of the fluid, that's exactly how mine looked when it failed, as Jono will verify, since he got covered in it at the Oxford meet. ( sorry again Jon )

[gb_brown]

Got it back in under a week, at no cost, well done PNM. Though only just had time to re-fit it.

So I have a working clutch again, which is nice So if anyone else is in a similar situation probably worth giving PNM a call.

Gareth