Defender 110 - Slipping clutch - Tech help?

Hi All - the Clutch on my Def 110 seems to have started slipping - I had a new one installed last summer - all well, and it has been treated very well.

Today had a mini service done, checked all levels (incl. clutch) - then driving back from specizlist, the clutch started slipping in 4th & 5th gear.

Pressed the pedal a few times - the problem disappeared for a few minutes. Then it came back again.

Could it be that upon opening the clutch liquid resevoir some air bubble has been created in the circuit that prevents the slave / master cylinders to have enough pressure with the plates? What can be done? Of course this comes as I am preparing to drive to South Europe from London for Xmas

Any help gratefully and urgently received!

GG

Check free play on the master cylinder push rod.
The slipping in 4th thats how mine started, checked free play, free play present damn! so fitted new clutch.


Lynall

Try bleeding the system, as you might have an air lock make it's way to the slave cylinder!

Hope this helps.

Slipping in 4th and 5th sounds like contamination of the plate, if you are not losing clutch fluid then maybe rear seal on crank or gearbox leaking, is the wading plug out and are there any sign of dripping ??

Cheers Steve

and going away suggests the contaminant burnt off on slipping but the plate became re-contaminated as you continued.

Cheers Steve

having air in system wont make clutch slip as the hydraulics only disengage clutch , not engage it , the diaphragm spring is what pushes the plate into contact with flywheel. So the only way pedal could affect clutch to make it slip is if you have no free play on system
Check that pedal has free play , you should get bit of light pedal movement before it starts to feel resistance as it pushes on diaphragm . If you have this then it must be 1 of two things , oil etc on plate or diaphragm spring in pressure plate is u/S did you have all new parts fitted when it was done ? HTSH

free play in the rod also wont make the clutch slip.
the system is pressure to release not pressure to engage. so if there is a fluid pressure build up in the system the thrust bearing would always be pushing on the cover, making the grip less effective, thus slipping.
likewise if the pressure plates springs have gone weak.

another theorey is that the thrust bearing may be sticking on the gearbox input shaft and not returning properly, having the same effect as the pressure build up. the way to rule this out is when the clutch slips, quickly press the pedal about half way down then side step off the pedal, this will push the thrust bearing out the way quickly with less chance of it sticking forward.

either way im sorry to tell you seems to me like its a box out job. unless the pressure build up is the case, which all you need to do is very lightly crack off the bottom bleed nipple, and if fluid spurts out, there was a pressure build up, and it should be fine again afterwards. ive had this problem as a result of using a pressure bleed system on the clutch system.

worth adjusting push rod for master cylinder in pedal box under top plate too much adjustment towards end of rod can cause fluid not to return to reservoir quick enough ratchetting on clutch ,unlikelt to be oil on plate as rear main seal leaks down the back of fly wheel and unless wading plug left in never goes near clutch, some slaves need shim in between bell housing and cylinder (std part ) or as said maybe poor clutch ,to adjust rod you need cheap combination spanner with slot cut in ring end o go over rod,its best to start will alot of free play and adjust to reduce it

Dear all - trhanks for responding so quickly - I am reviewing this with my specialist tomorrow morning prior to leaving for a new 2k miles round trip tomorrow (isn't always the case!!!!)

Thanks all!

GG

All hydraulics rod & pedal adjustments have been checked - all ok. I am told unlikely oil seeping in, also, 2yrs ago when replaced clutch, the old one was shot but bone dry.
Another possible cause may be the fact that the engine (slighly tweaked 2.8 Isuzu TD on LT85 / LT230 Disco boxes + Allisport Intercooler) delivers too much torque - and likely the clutch discs / pressure plate that i had fitted 2 yrs ago was an aftermarket one and not strong enough - I am now in the middle of nowhere in france and driving south, a bit of slip, but still ok overtaking lorries at 70mph tomorrow I am crossing the mountains so we'll see if the engine tries to leave the car behind!
When back I will be having the conversion plate modified to accept a proper LR V8 Heavy duty clutch (any suggestions re. who can do it apart from MIlner conversions/) That'sll be a post Xmas present!
Thanks again!
G

hi, if you have the standard land rover defender clutch plate and cover, i would consider getting a 130 HD clutch kit, as it should bolt straight in. thee pedal might feel a bit stiffer but i think it will be worth it.