Mondeo MK4 Clutch Master Cylinder

[Onoff]

Life gets better. Went to pull away from the hospital car park and the clutch master cylinder went. 10 year old car ffs!

I'm pointing to the bit of broke plastic. Like a cross close up. That hinges on a shaft on the clutch pedal and connects at the bulkhead to the master cylinder.

Any reason why it's a seeming weak point and destined to fail? Hope it's not the clutch itself stiff / failing

Some hope getting one on a Sunday

 

[500e]

2 of the Fiat Doblo vans we had they used plastic push rods on the clutch total S***, dam accountants made new metal ones simple enough, the plastic bit was not a spare, part of the MC
You could just change it without removing MC it was holding in the piston when removing circlip while standing on your head was the hard part

 

[johnik]

this fella looks after a fleet of mondingo,s, might be worth a trawl through his stuff as i seem to remember him replacing one at great expense

 

[Nick67GT]

Looks like a classic fatigue failure to me.

 

[Onoff]

It's a steering cover column covers off, dial pod out, steering column removed job to do it. Found one YouTube video:

https://www.google.com/url?sa=t&source=web&rct=j&url=https://m.youtube.com/watch%3Fv%3Dws6e9s0dKIw&ved=2ahUKEwiwmI-6r9f5AhXHQcAKHQ2IBX0Qxa8BegQIBBAE&usg=AOvVaw0WyNukGQ52TIA6SJ4Ps92w

From Ford it comes as a complete part with the pedal like this:

The part that's broken dead centre of the picture:

 

[Wildefalcon]

That's a bit of Lego. Crap design. Ford philosophy: what spare parts don't we sell? Make them cheaper! From the days of the model T.

 

[Onoff]

That's a bit of Lego. Crap design. Ford philosophy: what spare parts don't we sell? Make them cheaper! From the days of the model T.

I had a similar issue with a MK1 Focus. The plastic piston connects to a steel pin welded to the clutch pedal arm. In that case the weld was so poor from day one, the pin broke off. Destroyed the plastic piston arm.

 

[droopsnoot]

On my TT, the master cylinder actuating rod sits in a bracket which is spot-welded to the side of the clutch pedal. The part that actually takes the pressure is just folded over, though, not welded at all. Actually, maybe people on here would have enough understanding of such things to be able to tell whether this is - as I suspect - just a rubbish idea.

I'd post a photo, but I can't find one. Picture a top-hat section with a spot-weld on either flange to hold it to the pedal side. One "end" is then folder over, and it's this plane that takes all the pressure.

 

[Onoff]

On my TT, the master cylinder actuating rod sits in a bracket which is spot-welded to the side of the clutch pedal. The part that actually takes the pressure is just folded over, though, not welded at all. Actually, maybe people on here would have enough understanding of such things to be able to tell whether this is - as I suspect - just a rubbish idea.

I'd post a photo, but I can't find one. Picture a top-hat section with a spot-weld on either flange to hold it to the pedal side. One "end" is then folder over, and it's this plane that takes all the pressure.

Considering where they are, are these parts meant to be a weak point as in they break in the event of an accident rather than sharp, unyielding metal bits coming into your lower legs etc?

Whatever, picking up an OEM part today £60+VAT.

 

[Blobber]

Thats cheap enough even if it is a pain to change!

 

[Onoff]

Thats cheap enough even if it is a pain to change!

I thought I was getting the part above i.e master cylinder c/w all the mechanicals. The one above was on eBay for £59.99 all in and posted.

All I have from my local factor is the cylinder at £72.00 inc VAT.

Was hoping to see if I could get the broken part out of the existing master cylinder, it's a plastic ball that pushes into a socket with tabs. Thinking 3D print a removal tool using the new unit to measure from.

Then compare the removed, broken one to the one on the new cylinder and if the same fit the new rod/ball to the old cylinder.

However...there is zero movement on the tabs to be able to get the ball out

 

[anto44]

Was hoping to see if I could get the broken part out of the existing master cylinder, it's a plastic ball that pushes into a socket with tabs. Thinking 3D print a removal tool using the new unit to measure from.

Then compare the removed, broken one to the one on the new cylinder and if the same fit the new rod/ball to the old cylinder.

However...there is zero movement on the tabs to be able to get the ball out

I dismantled an old VW one for the same reason, to see if I could change the rod instead of the whole cylinder.
On the VW one which looked identical to the one you have, the rod is fitted to the piston before the piston is inserted into the cylinder, once the piston is in the bore the tabs can't bend outwards to release the rod

 

[Onoff]

Well this is fun!

The master cylinder is sandwiched between bulkhead and clutch assembly bracket. Thus you have to take the clutch bracket off. Of course before you do that you have to take the steering column out. I'd like 5 mins with the moron at Ford who designed this!

It gets "better"...

The clutch assembly bracket is held on by 3 M8 "bolts", we'll call them bolts but that's an affront to bolts. The heads are completely round with no hex slot. Trying to undo that nut dead centre below and that and the bolt just span round.

Had to whack 2 back to back M8 nuts on the end to undo the one original. Even then I had to grip it with a pair of moles at the end.

Going to need a new bolt there. Might have to get someone to machine me a cap head bolt so I can get an Allen key in from the other side.

That leaves two nuts to get off. One came off easy enough. For the other I've taken ages effing and blinding. Only just seen the subtle, square access hole in the dash about 12" from where the nut is. Haven't got a 1/4" extension bar that long though.

 

[Onoff]

There's a box section (well, 3 sides with flanges) that goes across the bulkhead in the engine bay. It's insulated over, guessing a heatproof mat.

Through it you can see the bolt head.

It sits just below the master cylinder. The face of the box is about 3" from the box face. I popped the endoscope through it whilst my lad rotated in from inside the footwell. Basically no way of gripping it from this side.

Thinking get an M8 cap head screw and fit that instead.

Video clip link:

https://flic.kr/p/2nFRXdJ

 

[Onoff]

Have I made a mistake? That bolt that's spinning, that doesn't have a head you can grip, is it that that black bit on the end is (was ) a small hex you could put a nut runner on?

I've now rounded it off with the moles maybe?

Old eyes and not thinking straight. Tbh I'm knackered from hospital visits and more than a bit stressed.

Just "didn't think" perhaps? Maybe I should have used the endoscope to see that close.

Hoping to get the bracket off tonight finally. Two nuts off and one to go though that seems too be coming off. Left it last night with a drop of finger applied (worst access of the 3), ACF-50 as it was a bit tight. Didn't want it spinning like the other one!

 

[johnik]

so glad i am retired now and dont have to put up with such pointless designs any more

 

[droopsnoot]

Well this is fun!

The master cylinder is sandwiched between bulkhead and clutch assembly bracket. Thus you have to take the clutch bracket off. Of course before you do that you have to take the steering column out. I'd like 5 mins with the moron at Ford who designed this!

I feel your pain. The workshop manual for my car doesn't refer to the RHD models at all, and there's easy access to the master cylinder on the LHDs ones, those from where all the designers live and work. On the RHD cars, it's down there somewhere:

The yellow cap is the top of the fluid reservoir - which cannot be filled without a long tube, if you don't want fluid all over the exhaust - and it's down and to the right (in the photo) from there. The heat shield in front of it doesn't come out without major dismantling of other parts.

 

[Onoff]

Looking at the bolt sat against the silver plate with the slot in, just behind the steering column and I'm thinking there is indeed a black hex head on the end:

I'll try and double check with the phone camera when I get home. I'll be kicking myself if there is as I've made myself a shed load more work. Not thinking too straight at the mo and tbh could do with the car.

Another evening of fun ahead!

 

[Onoff]

I feel somewhat better now. The black ends of the bolts are just round and pointed, no hex, no flats etc. Why do that to the ends, for what purpose?

Is it so you can get moles on them when the gits start to spin?

 

[Haz87]

If its anything like older Fords, that bolt will be welded to the bulkhead, so its ultimately acting as a stud. Shouldn't have any spinny spinny problems getting the nut off*
*unless Ford decided the 0.1p worth of weld holding the bolt in place cost too much and they've cheaped out