what causes a clutch to be heavy?

Rick-sta · 26th July 2017, 23:06

I had my clutch changed on my diesel ZT at the start of the year. it managed 191k on the original clutch so can't complain. However, my clutch pedal is still pretty heavy. It was lighter at first after the new clutch was fitted but very quickly went heavy again (although not as heavy as the old clutch was).

Didn't really think much of it but I drove another diesel ZT a couple weeks ago and the clutch on that was super light, barely had any weight on it at all. So when I went back to driving my ZT I realised how heavy my clutch is.

I had my clutch and slave replaced, master is still original and so is the DMF which was inspected and was ok. What could be causing it to be heavy? What actually causes a heavy clutch pedal?

RogerHeinz57 · 27th July 2017, 04:35

Chocolate clutch kits usually reveal themselves fairly quickly.Only other issues could be that the master was not evacuated of old fluid (Which may contain particles of master cylinder seals debris) or the slave cylinder sleave on the first motion shaft/input shaft has wear steps on it, causing the slave cylinder to not having a clean step free movement. These are very basic steps to observe by any fitter of clutches, standard procedure by Phil T-4 and myself.

See link, number 11.
https://www.rimmerbros.co.uk/Item--i-GRID001994

Westonboy · 27th July 2017, 07:33

I had a clutch issue recently on my cdt, I flushed half a litre of new fluid through the bleed system so the master was clean. after doing all that I found the slave was leaking so had a new slave fitted, my clutch is working fine but is just as heavy as ever, it has been the same in the 6 years I have owned the car. I have not driven another Rover 75 to make a comparison but when we had a peugot 308diesel the clutch was featherlight.

EastPete · 27th July 2017, 08:24

Quote:

Originally Posted by Westonboy

I had a clutch issue recently on my cdt, I flushed half a litre of new fluid through the bleed system so the master was clean. after doing all that I found the slave was leaking so had a new slave fitted, my clutch is working fine but is just as heavy as ever, it has been the same in the 6 years I have owned the car. I have not driven another Rover 75 to make a comparison but when we had a peugot 308diesel the clutch was featherlight.

Alan

Was the clutch kit (pressure/centre plate) changed at the same time as slave ?? Do you know what make of clutch slave and kit you have fitted ? Clutches will become a bit heavier as they wear, due to the extra pressure needed on the forks on the pressure plate that is required to release the driven plate.

75 clutches will always be a bit heavier than on other cars, in my experience, but with the right parts correctly fitted, they should not be that bad.

Thinking about it, were you the guy who contacted me about your clutch a while back, and you were taking it up to Jules to get it sorted ?

Cheers

Pete

EastPete · 27th July 2017, 08:33

Quote:

Originally Posted by Rick-sta

I had my clutch changed on my diesel ZT at the start of the year. it managed 191k on the original clutch so can't complain. However, my clutch pedal is still pretty heavy. It was lighter at first after the new clutch was fitted but very quickly went heavy again (although not as heavy as the old clutch was).

Didn't really think much of it but I drove another diesel ZT a couple weeks ago and the clutch on that was super light, barely had any weight on it at all. So when I went back to driving my ZT I realised how heavy my clutch is.

I had my clutch and slave replaced, master is still original and so is the DMF which was inspected and was ok. What could be causing it to be heavy? What actually causes a heavy clutch pedal?

Rick

I have PM'd you about this

Cheers

Pete

Number 6 · 27th July 2017, 08:55

I have posted about a similar "Problem"
Some days the clutch is feather light,another day it can be heavy from the start.
When it is light it will sometimes during the day get progressivly heavier.

The feeling I get is that there is a blockage in the system that prevents the fluid being pushed thru therefore needing more pressure to push the pedal down'

Similar to having a kink in a hose pipe the water flow is restricted until the kink is removed

Westonboy · 27th July 2017, 09:00

High Pete, I only had a slave fitted as the clutch assembly was only 8k old. Jules passed the repair on to a local garage that he uses and I am more than happy with the reusult, just commenting that the clutch is just as heavy as it was before, but perfectly ok.

Rick-sta · 27th July 2017, 13:50

I should have mentioned that the clutch kit fitted is the kit from DMGRS, Borg and Beck clutch with LUK slave.

The clutch itself is completely fine, works perfectly, get nice smooth gear changes etc. Was just curious why my clutch pedal is still quite a bit heavier than the diesel ZT I drove recently. Not sure when the clutch was changed on that or what was fitted, the master may have also been replaced on that so that could be a factor.

The fluid from the master wasn't drained I don't think when I had mine done.

Quote:

I have posted about a similar "Problem"
Some days the clutch is feather light,another day it can be heavy from the start.
When it is light it will sometimes during the day get progressivly heavier.

The feeling I get is that there is a blockage in the system that prevents the fluid being pushed thru therefore needing more pressure to push the pedal down'

Similar to having a kink in a hose pipe the water flow is restricted until the kink is removed

Mines the same, when I first set off the pedal is pretty light, but slowly gets a bit heavier.

Still it's not as heavy as it was before, was really heavy before used to hurt my left leg after a while in traffic. It's fine for me as it is but would have been lovely if it was as light as the ZT I drove recently. That one had no weight on it at all, super light.

DMGRS · 28th July 2017, 17:50

It seems to vary between manufacturers - I've driven a few we've worked on at the workshop with new clutches, and they've been pretty light.
I did drive a ZT with a Valeo clutch fitted, which was quite light too - possibly slightly lighter than our own.

It's all to do with the temper of the springs in the pressure plate.

Dallas · 28th July 2017, 18:08

Rick, I had three 190 ZT's, two with a feather light clutch and one with a stomping heavy clutch, neither had history of a clutch change.

Guest which one I have kept?

26th July 2017, 23:06	#1
Rick-sta This is my second home MG ZT 2.0 CDTI+ in Typhoon, MG TF 135 in Typhoon & Rover 75 Connoisseur CDTI SE in Pearl Black Join Date: Oct 2012 Location: Norfolk Posts: 7,532 Thanks: 2,718 Thanked 2,827 Times in 1,462 Posts	what causes a clutch to be heavy? I had my clutch changed on my diesel ZT at the start of the year. it managed 191k on the original clutch so can't complain. However, my clutch pedal is still pretty heavy. It was lighter at first after the new clutch was fitted but very quickly went heavy again (although not as heavy as the old clutch was). Didn't really think much of it but I drove another diesel ZT a couple weeks ago and the clutch on that was super light, barely had any weight on it at all. So when I went back to driving my ZT I realised how heavy my clutch is. I had my clutch and slave replaced, master is still original and so is the DMF which was inspected and was ok. What could be causing it to be heavy? What actually causes a heavy clutch pedal? __________________ How to retrofit Cruise Control on a diesel with no OEM wiring in place: Link How to retrofit heated electric memory seats with no OEM wiring in place: Link How to operate FBH and ATC via text Link How to restore cloudy projector headlights Link

27th July 2017, 04:35	#2
RogerHeinz57 I really should get out more....... A Reasonably Priced Car Join Date: Jan 2014 Location: Burton Latimer Posts: 2,530 Thanks: 408 Thanked 1,064 Times in 712 Posts	Chocolate clutch kits usually reveal themselves fairly quickly.Only other issues could be that the master was not evacuated of old fluid (Which may contain particles of master cylinder seals debris) or the slave cylinder sleave on the first motion shaft/input shaft has wear steps on it, causing the slave cylinder to not having a clean step free movement. These are very basic steps to observe by any fitter of clutches, standard procedure by Phil T-4 and myself. See link, number 11. https://www.rimmerbros.co.uk/Item--i-GRID001994 Last edited by RogerHeinz57; 27th July 2017 at 04:38.. Reason: Further info added

27th July 2017, 08:55	#6
Number 6 This is my second home Rover 75 tourer Club CD/Limo Tints Join Date: Nov 2008 Location: Meneac Posts: 6,759 Thanks: 5,007 Thanked 1,609 Times in 869 Posts	I have posted about a similar "Problem" Some days the clutch is feather light,another day it can be heavy from the start. When it is light it will sometimes during the day get progressivly heavier. The feeling I get is that there is a blockage in the system that prevents the fluid being pushed thru therefore needing more pressure to push the pedal down' Similar to having a kink in a hose pipe the water flow is restricted until the kink is removed __________________ ] "I started out with nothing, and Ive still got most of it left!"

28th July 2017, 17:50	#9
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,320 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	It seems to vary between manufacturers - I've driven a few we've worked on at the workshop with new clutches, and they've been pretty light. I did drive a ZT with a Valeo clutch fitted, which was quite light too - possibly slightly lighter than our own. It's all to do with the temper of the springs in the pressure plate. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

27th July 2017, 07:33	#3
Westonboy Posted a thing or two Honda Jazz Join Date: Jan 2012 Location: Llangollen Posts: 1,025 Thanks: 301 Thanked 344 Times in 158 Posts	I had a clutch issue recently on my cdt, I flushed half a litre of new fluid through the bleed system so the master was clean. after doing all that I found the slave was leaking so had a new slave fitted, my clutch is working fine but is just as heavy as ever, it has been the same in the 6 years I have owned the car. I have not driven another Rover 75 to make a comparison but when we had a peugot 308diesel the clutch was featherlight.

27th July 2017, 09:00	#7
Westonboy Posted a thing or two Honda Jazz Join Date: Jan 2012 Location: Llangollen Posts: 1,025 Thanks: 301 Thanked 344 Times in 158 Posts	High Pete, I only had a slave fitted as the clutch assembly was only 8k old. Jules passed the repair on to a local garage that he uses and I am more than happy with the reusult, just commenting that the clutch is just as heavy as it was before, but perfectly ok.

28th July 2017, 18:08	#10
Dallas This is my second home 1979 Capri 1.6L, 1982 Capri 1.6L, 2016 Dacia Stepway Join Date: Jun 2009 Location: Dorset Posts: 8,595 Thanks: 3,496 Thanked 3,397 Times in 2,218 Posts	Rick, I had three 190 ZT's, two with a feather light clutch and one with a stomping heavy clutch, neither had history of a clutch change. Guest which one I have kept?