Adjusting the clutch; refilling the steering (PAS) system

Not so much on adjustment... more on unexpected problems! I will post more on adjustment if and when I cure these problems.

Well gentle reader... its getting on to the moment of truth- and I have to admit part of me keeps finding other things to do rather than press on with the task of recommissioning. However- clearly I can't drive the car without steering or clutch so I will need to tackle these. Steering is the more tricky- it might be OK now I have rerouted the hoses and tightened up all the unions, but as this is a bit of a gamble I thought I'd try the "easier" clutch adjustment first!

Ha....!

As you will recall I have fitted (refitted) a replacement clutch with very little wear. I have also fitted a new master cylinder and a new slave so I hadn't expected any problems. The parts manual seems quite clear; the clutch m/c is not located behind the pedal but offset a considerable distance to the right. This means that the pedal can operate the cylinder only by means of  a horizontal extension bar at the top of the pedal that extends across and above both brake and accelerator, to leave the pedal box on the right to join with the master cylinder push rod.  This extension is bent down at the end and drilled to engage with the trunnion on the end of the push rod and the two are secured with a clevis pin.

Similarly the WM is clear There are only two adjustments to be made to the clutch; the slave cylinder push rod is adjusted so that full travel is achieved just as the pedal reaches the carpet during depression- and the pedal itself is adjusted at its upper limit of travel so that there is around 1 cm free play when the pedal is in the "up" position before it starts to move the clutch. This ensures that the clutch isn't being pre-loaded by the pedal. This seems easy enough... although I do wonder about the possibility of actually adjusting both ends of the movement. This is because the push rod is metal and doesn't stretch! If you set the pedal to max push rod movement at the pedal down stroke, then since the push rod is of fixed length (and backwards movement is limited by the holed washer inside the M/C), then the  "up" position must also be fixed. Further the amount of free play obtainable is fixed and limited to the amount the push rod can move between contacting the piston inside the M/C (forward), and jamming on the holed washer (rearwards). Consequently, I can't see what relevance the up-stop adjuster can actually have? However I have adjusted many clutches before so I set about this task with confidence....  BUT this time there was a large and very obvious problem!

The clutch pedal was sitting well below the other two pedals-in fact its only about an inch from the carpet even with the push rod adjusted to its maximum length.

View of pedals- clutch pedal sitting well below the other two.

In fact the pedal's upwards travel appears to be limited by the clutch m/c push rod itself and is still over an inch from the so-called up stop! It can't be pulled any further upwards unless the push rod is first disconnected.

View from drivers foot well- a view I have come to know well! This is looking upwards and towards the front of the car at the pedal box. Pedal shaft visible running vertically on the left in the picture is the clutch pedal.The  head of its up-stop adjuster bolt visible at bottom centre with clutch pedal return spring behind. Note shaft of pedal is well clear of the up-stop adjuster and the up-stop isn't even long enough to unscrew to control this position. There are some rusty tell-tale marks on the shaft of the pedal suggesting that the pedal has been in contact with this bolt head in the past.

As well as this problem with upper travel limit, there is an alignment issue: The push rod is attached to the extension of the clutch pedal by means of a clevis pin and fork shown below. The angle of the push rod does seem awkward- the workshop manual shows this as almost horizontal and directly in line with the cylinder whereas here its clearly not. The push rod has to deviate to the right (left in this pic) and upwards to enter the m/c. Furthermore it doesn't appear to enter cleanly, if the pedal is pressed the rod seems to jam on something inside the master cylinder; it catches and then pushes past again with a noticeable clicking/grinding. I suspect the angle of entry is causing the push rod to foul on the holed washer that it passes through inside the cylinder and which retains it inside the cylinder.

View from driver foot well looking upwards and towards the engine. The rear of the clutch master cylinder is visible with  its push rod connecting to the extension of the clutch pedal. Note awkward looking angle as the push rod has to angle right (left in this view) and upwards to engage the master cylinder.

second view of misalignment

In fact the push rod seems to sit more naturally alongside the clutch lever extension rather than actually straddling it. In the view below note how the line of entry is straightened if the rod trunnion is held against the clutch lever extension rather than straddling it- clutch lever extension visible between my index finger and thumb. This again suggests the lever extension is too short.

Looking up from driver's foot well- clutch m/c push rod disconnected but held against clutch operating pedal extension. Line of entry straightened.

If the clutch push rod is disconnected the pedal springs immediately back against the up-stop. Its smooth in operation and there is no trace of a bent lever- which is not apparently unknown in these cars. 

It seems that one explanation is that the clutch pedal horizontal extension just isn't long enough. However there seems to be nothing missing from the clutch pedal and no sign of it having been cut short or bent out of position.  However my enquiries have revealed that it can bend or twist across the top of the box and on the arm. This means the pedal shaft itself may not be bent and its movement on the pivot shaft may not be compromised even though the lever is bent! This type of damage isn't necessarily visible unless you remove the box.

Alternatively, and my first thought, perhaps the push rod is too short? ...I removed it from the M/C and compared it with my old one... but its the same length!

Comparison of old and new cylinder push rods, LH is my old one and the RH is the new- they are pretty similar and even their trunnions are the same size. Note the domed end to the push rod which limits backwards movement of the rod when the pedal moves up. .

Finally, might the clutch be half depressed for some reason thus pre loading the cylinder? However, the clutch operating arm in the bell housing does have some free play so the clutch itself isn't under pressure.

Overall then at the moment I am a bit puzzled- I suspect I could straighten the angle using a bolt to extend the clutch lever sideways and slip the trunnion over this- that would line up the rod better, although it would create an awkward loading. However this would do nothing about the lack of free travel in the pedal. 

 I am indebted to the forum for considering my problem- the ideas suggested are:
1. Bent pedals ... not obvious...
2. Pedal has moved to left (no evidence that clutch has moved closer to brake pedal, and the whole box can't have moved because there is no room to move the accelerator farther to the left.
3. Pushrod length (see above)
4. Wrong box- the design of the pedal box was changed in '86- perhaps this box/pedal has already been replaced when a previous clutch pedal bent, but the wrong one was fitted? I have checked with Lotusbits who tell me several (8) redesigns were made on this component. However these seem to have affected the  mounting arrangements and brake travel rather than the clutch.
5. M/C fitted wrongly... long shot as this isn't really possible. I've checked it anyway though.

Its looking like more and more like a bent pedal... especially as I have found other reports where the extent of the bend wasn't obvious before removal. I checked out my own blog as to how the thing was when I received the car- I knew these blogs would come in handy! I didn't take so many pics then but looking back at the entry "Clutch hydraulics" shows that in fact the pedal was disconnected when I got the car and the M/C at that time was full of muck (probably siezed). Its likely therefore that the LBPO knew full well that this was a problem and  simply "forgot" to mention it.  I will have to remove the pedal box and probably change it... and I have tracked down the correct box for the year from Lotusbits. However I do worry about the wisdom of simply replacing a bent box with another identical box when they are apparently quite weak structurally. Consequently, I might also see about welding some reinforcing fillets to strengthen the pedal and arm if there is enough room.

By all accounts swapping a pedal box  is a pig of a job and certainly one I hadn't reckoned on doing! I will make a separate blog entry for that job.


Refilling PAS
My WM has no section on steering- seems a bit of an oversight but its possible that my manual has simply lost it. Anyway I do have a section from the Elite and so I'm assuming this procedure will be fine for the Excel.

In the meantime I have tightened and repositioned all  hoses in the hope that leaks might be avoided!

1. Fill reservoir with fluid- I'm using Halfords cheapest! (DII).
2. Disconnect coil positive lead and fuel pump, and  crank motor a few times. Top up and repeat until topping up is minimal.
3. Start motor and run for a short while- I did about 20-30 sec. Top up and repeat until level is stable.
4. With motor running turn steering from lock to lock a few times until no bubbles visible in reservoir. (Care if front wheels raised)
5 Top up again if necessary.