EOW 1W MATRA 1.9 RESTORATION

[TELBOY]

As she stands!

[TELBOY]

Decided to dismantle clutch master cylinder to replace seals.....cat had other ideas!!!!

[TELBOY]

So lets think about this!!!! Clutch master cylinder repair kit from Simons.....13.9euro +20 euro postage!         Complete NOS clutch master cylinder listed for a Baggy £25 + £4.50 postage (the later version so it fits the baby Murena)...... Absolutly no objection to Simons prices but postage 20euro!!! come on....

[TELBOY]

Two steps forward, one step back:-
This mornings easy job was replacing brake pipe clips:-
Whist undertaking this simple task I discovered that the fuel tank straps had disappeared, no doubt into a pile of rust somewhere!!!  

[TELBOY]

Could someone please advise me if I have done this correctly before its too late to change? When I fitted new brake pipe from left to right at the rear last year , I threaded the pipe through 3 gaps in the chassis. However the old pipe was just below this supported just by ty-wraps! Have I done this correctly? The old ty-wraps can still be seen at both ends (only one photo came out) But I drilled and fitted brake clips!!!

[Bart_Maztra]

Check which size bore clutch master cylinder you have.  There are 3 bore sizes around.
Make sure the repair kit is the same.
Also when going for a replacement cylinder, make sure the bore is the same.

I had mine cylinder replaced, and found the clutch pedal much harder to press. Turned out the replacement cylinder was bigger than the old one. 
http://www.matrasport.dk/forum/index.php/topic,1420.msg10726.html#msg10726

[TELBOY]

Thanks for the advice B-M I checked with Roy first (as I always do) Mine is the correct one (19mm) Unfortunatly Roy didn't have any repair kits and I point blank refused to give Simons 67.9 euro for the piston kit (including postage) I found a nice man after searching for 8hrs on the interweb and purchased his entire stock of the same piston kit. They have the same I.D numbers stamped on the pistons and worked out at a third of the price!!! I plan to pass these on to members if there is any interest. I am also paying him a visit today as he says he may have some NOS master cylinders so am taking mine down to compare. Again these work out at less than a third of the price and cheaper than simons repair piston kit!!!! Will keep the forum posted (and the owners mag)
Tel

[TELBOY]

Just got back............well, the casing and mounting points were identical, but, He allowed me to remove the piston and we measured it to find it was 22mm. He showed me a rather oilr and dusty book which listed this part as for a Bagheera and simca 1000..........surely this cant be right? I thought the baggy had the same diameter piston as the Murena 1.6! Anyway photo of mine stripped and ready to clean and fit new piston spring washer and circlip.

[TELBOY]

so puzzling over this all day I went back and purchased one for the hell of it!!!!!! So:- obviously the mounting is identical and all pipe attachments are correct! Therefore being a larger bore it should displace more fluid when activated causing problems at the slave end, correct?
But....as can be seen in the photos the bore of the piston passed the seal is increased so taking up space which would otherwise be full of fluid....therefore the amount of fluid displaced when the clutch is pressed and the piston moved "may" well be equal to the amount of fluid displaced in the smaller cylinder.
Or to put it as archimedes did. an article placed in a liquid will displace its own volume of liquid.
There is a way of testing this but I havnt got the time at the moment!

[suffolkpete]

The volume of fluid displaced is  equal to the area of the piston face (3.142 x radius squared) x piston travel.  The larger volume of fluid displaced will make the clutch action heavier and possibly push the slave beyond the end of it normal travel.  I wouldn't use it.

[TELBOY]

Hi Pete
Your calculation of Pie r sq would be correct if there was no intrusion passed the end of the piston, but, as stated both pistons have a protrusion passed the end of the piston with the 22mm much larger therefore displacing much more fluid. The amount of movement at the slave cylinder would be determined by the volume of fluid displace as we agree but these volumes may be the same. I don't intend using it as I have the 19mm one which now has new piston and seals fitted, but for my own interest I will be filling both with fluid replacing the pistons and seals and checking the volume of fluid both hold
Will let you know the results, but it is really intriguing me.
Tel

[suffolkpete]

The protrusion doesn't make any a difference to the volume displaced, it simply means you start off with a smaller initial amount, but the displacement is the same.

[TELBOY]

Agreed... Will hang onto it as i got it as an experiment and it has the same mountings.  You never know,  if my slave goes I'll get the matching one. LOL
TEL

[roy4matra]

Agreed... Will hang onto it as i got it as an experiment and it has the same mountings.  You never know,  if my slave goes I'll get the matching one. LOL

You can't Terry.  The 1.6 and 2.2 slave cylinders are totally different.  The 1.6 (or Simca/Bagheera/Rancho etc.) slave cylinders are bolted to the bell housing casing with two 8mm bolts, whilst the 2.2 slave has no flanges where bolts could be fitted.  It is purely cylindrical and slid into a circular casting and held in place with a large circlip.

For information a 1.6 slave has a 25.4mm bore and the 2.2 slave has a 28.6mm bore.

Roy
P.S. I have plenty of these circlips if any 2.2 owners needs one: £1

[TELBOY]

You will all be pleased to know that the clutch master is now repaired and in perfect operating condition. As EOW is a 1.9 pug engine with the relevant slave cylinder it might be possible if I ever needed to fit a different slave, but all this is really me just thinking out loud, and being reluctant to pay Simons prices (postage) but it does appear that there is no option if I ever need a new master cylinder. but, and I am being seriouse for a change!" as it appears there are plenty of the larger bore cylinders is it possible to press a machined tube into the bore to make it the correct diameter? the holes for the fluid could be drilled ounce in position!!! I had a look ont interweb and it appears that these tubes can be obtained and as a larger diameter bore master cylinder can be found for around £25 it would work out a cheap alternative! again me thinking out loud but as I now have a larger master it is something I will experiment on just for the hell of it.. Advice / ideas more than welcome.