27 replies to this topic

[absx2]

 

I guess I over thought that one and it turns out my rod length was to blame.

 

 

 

How so?  The master cylinder rod/plunger?  Which master cylinder have you got fitted?

 

I assume it`s  a http://www.minispare...|Back to search

 

But it could be one of these depending on how much longer the rod actually is ?

I didn`t buy it but it was new a few years ago when I got the car.

http://www.minispare...|Back to search

[Spider]

I have found the issue was caused by my push rod length as it was long enough to wear a little dent into the bulkhead.

 

R Clips and Split Pins aside, you need about 2 - 3 mm clearance here from the pedal / push rod clevis to the bulkhead when you don't have your feet on the pedal. This is to ensure the seals in the Master Cylinder are below the ports in the bore that lead back to the Reservoir. If these are covered or above the Ports, the Brakes will tend to pump themselves on as you drive and not release.

 

In UK manufacture they had a rather thick Gasket between the Master Cylinder Bases and the Base Plate and I'd say, that gasket is fairly critical here to achieve that required clearance. We actually had shims that they would fit in our local production, as required.

The Clevis Pins have only ever been long enough to get a retaining Pin (R Clip or Split) in without a Washer, as you've found.

 

The only R Clip I had come out was the middle on in my photo (previous page). When I fitted it, I never gave it a second thought. It actually came out when I was away on a trip and in some billy goat country. I didn't know until one time going for the brakes, I found the take up on the pedal was considerably lower, luckily it seemed the pedal clevis balanced on the end of the pedal ! It was only when I pulled over and looked I found the R Clip and Pin rolling around on the floor. That sure drew my attention to these Clips and what the issue was.

Just out of interest, here's a page from our local Parts Fiche, item 16;-

 

 

I can see from the P/N Prefix that it's a locally designed and made part.

 

[Mr Piggy]

You guys probably know this already but the trickiest bit if removing or fitting a split pin is straightening or bending the legs. If you pull up on the pedal it'll stop the clevis pin rotating and make bending the legs with a screwdriver easy.

 

Alan.

[absx2]

 

I have found the issue was caused by my push rod length as it was long enough to wear a little dent into the bulkhead.

 

R Clips and Split Pins aside, you need about 2 - 3 mm clearance here from the pedal / push rod clevis to the bulkhead when you don't have your feet on the pedal. This is to ensure the seals in the Master Cylinder are below the ports in the bore that lead back to the Reservoir. If these are covered or above the Ports, the Brakes will tend to pump themselves on as you drive and not release.

 

In UK manufacture they had a rather thick Gasket between the Master Cylinder Bases and the Base Plate and I'd say, that gasket is fairly critical here to achieve that required clearance. We actually had shims that they would fit in our local production, as required.

The Clevis Pins have only ever been long enough to get a retaining Pin (R Clip or Split) in without a Washer, as you've found.

 

 

 

Excellent as always Chris and a very good point about the necessary free travel on the brake cylinder.

Mine being the clutch I left it alone and I tried to find a washer that I wouldn`t normally bother with because I thought I would be shot down in flames if I didn`t    

[tmsmini]

I think you will also find that some of the clevis pins are coming with larger holes than original which makes fitting an R clip more complicated.

[humph]

I think you will also find that some of the clevis pins are coming with larger holes than original which makes fitting an R clip more complicated.

Sorry for being thick, but could you explain why please?

[tmsmini]

I wish I had saved a picture from a few years ago.

With a larger hole in the end of the clevis pin, the smaller r clips will not fit properly. The larger ones will fit snugly, but then they will eventually foul on the bulkhead opening for the master cylinder push rod mechanisms.

[nicklouse]

I wish I had saved a picture from a few years ago.

With a larger hole in the end of the clevis pin, the smaller r clips will not fit properly. The larger ones will fit snugly, but then they will eventually foul on the bulkhead opening for the master cylinder push rod mechanisms.

I have some old and new ones. Will have a look.

[Tornado99]

There are other sorts of clips and even special pins with spring-loaded locking toggles as alternative to cotter/split type pins.

In this application, perhaps the below "Bow-Tie" type clips would be better than R-clips: 

 

[A-Cell]

PLEASE don't fit R pins to this safety critical fit meant. See this old forum topic
https://www.theminif...teering-column/

[johnv]

PLEASE don't fit R pins to this safety critical fit meant. See this old forum topic
https://www.theminif...teering-column/

 That topics ends with the conclusion that it is safe to fit them as long as they are the correct spec.

[A-Cell]

I cannot condone the fitment of an R pin to either the brake pedal or clutch pedal Clevis pin. Only use a split pin otherwise there is a severe risk of failure.

[Spider]

I cannot condone the fitment of an R pin to either the brake pedal or clutch pedal Clevis pin. Only use a split pin otherwise there is a severe risk of failure.

 

That's fair enough and if one is worried by them, then use split pins for sure.

 

I should have added to my other posts here on R Clips, that if used, to always check them after fitting that they can't pop out by contacting the bulkhead or anything else. This check should be done not just in the relaxed position, but also with the pedal on the floor. They need to have a few mm clearance to allow for wear.

If that ^ can't be achieved, then I'd suggest split pins as A-Cell strongly suggests. Regardless, these would be far more reliable in any circumstances.