Is MC Girling 875 original

[am99ey]

Does anyone know if my break MC is an original for a SV 1966?
The installad MC carries the letters "GIRLING 875" und "7326 035".

I decided to redo or exchange the break MC, don't know yet which solution I will take yet. Sleeve, rebuild kit, buy new ...

Thanks for an opinion.


PS: Still battling with the disfunction of my breaks after having rebuilt the Girling Servo MKIIA / 7".

 

[todd reid]

875 Mc

Girling 875 means you have a 7/8" bore master cylinder, which was the standard size on Series V's. It may be the original or a replacement, but you do have the correct part.

 

[am99ey]

Thank you Todd. What do you suggest to do with it?
Sleeve, just rebuild with repair kit, or buy a new one of equivalent type?
Is there a difference in quality from yesterday to today's material. Don't want to step backwards and throw away a good piece.

 

[todd reid]

mastercylinder

The cylinders are pretty simple internally, and can be rebuilt by the owner without any special tools. You may want to start by opening up your existing cylinder and examining it. The two critical areas to look at are the cylinder bore (look for signs of scratching or scoring ) and the springs which can wear down (they should be uniform in size with no sharp edges). If all looks good, then your cylinder may be a good candidate for a rebuild (more accurately a reseal).
In the US, seal kits run in the neighborhood of $10-12, and replacement cylinders approx 10 times as much. At these prices, it really doesn't make sense to resleeve - a new cylinder is cheaper.
I am not aware of any technological advances that would make a new cylinder better, assuming that your old one is in good conition.
There are a couple of companies in the US (Wilwood, Tilton) that make functional equivilents of the Girling, if you have problems locating an original.

 

[am99ey]

The parts should be available here. I'll tackle it on on of the next few weekends. Thank's a lot, Andy

 

[am99ey]

MC is out on the bench now.
Can't get further than removing the rubber seal and the push rod. The circlip is out.
The main piston is not held back by a circlip or anything like that. How do I get that piston out ... hmm.
Thanks for a hint.
Andy

 

[skywords]

Sometimes a little corrossion has formed making it hang up. Compressed air carefully injected will pop it out, be careful and put a few rags around it when you do this. It can be like a zip gun so catch the parts.

 

[am99ey]

Thank you Rick, good to know.
Since I have no compressed air (kitchen table garage), I will try to "bang" it on a block of wood, gently. I hope it will get loose this way. My mechanic will have the proper equipment, as a fallback.
Andy
.

 

[am99ey]

... three bashes, and it came out, fairly easy. Was a bit rusty at the rim, as you said. Will take it to the machine shop for a light hone. Ricks (SS) rebuild kit shoud fit. I hope no problems occur.
Andy

 

[Ken Ellis]

Andy,
Do an advanced search on the word "hone" and the poster "jumpinjan" for some honing vs. polishing discussions before you turn over your MC to your mechanic. Just to be informed.

Ken

 

[am99ey]

After reading, I guess "polish" is the correct treatment, right?
Could not find any negative things about polishing.
Will also talk it over with the mechanic.

As I do most of the things on my SV have "once a lifetime" character, I do not have the experience to judge the exact consequences of my doings.
I'll take it step by step, no risk. Especially with the breaks.
Thank you again for your help and experience.
.

 

[V6 JOSE]

... three bashes, and it came out, fairly easy. Was a bit rusty at the rim, as you said. Will take it to the machine shop for a light hone. Ricks (SS) rebuild kit shoud fit. I hope no problems occur.
Andy

Why not just get a new one? They are very cheap, about $45, and you will rest easy. I know that some guys prefer to do it themselves, but if it had rust inside, the chances that the bore isn't pitted, are pretty slim. You don't want to fool with your brakes, so if you're not a professional at rebuilding brake parts, I would recommend buying a new one. Remember, you would have to disassemble it all again, if you didn't manage to fix it properly. I would suggest doing a search for Wilwood, they have direct bolt on replacement master cylinders for the Alpine.

Jose

 

[am99ey]

Jose, I think the same. We have a well known company here who did have a good reputation on doing a good job on rebuilding breaks and clutches (probably equivalent to wilwood). They have subsidiaries in the major cities here in Switzerland. But since all the good old guys retired, I have difficulties even buying a V belt for an "Sunbeam Gas Grill" *LOL*. Staff only knows how to hack on the computer. Btw they quoted me a M/C Girling 875, for $360 (three six zero). Never again going back there, promised.
I found a supplier in Germany quoting $90, not bad for a fallback solution. Just the bother of importing bits and pieces, as crossboarder allways means customs and vat and all that fuss.
I have a SS rebuild kit in the drawer, so I wil do it my self. My mechanic will not take risk on safety and tell me if rebuilding is not worth it. The M/C should be back to me next monday.
After all this, I am still enjoying beaming!

PS: The speedo of my Audi jumped 333'333 km just yesterday.

 

[Bill Blue]

Hey, wait a minute. If I remember correctly. Jan's admonishment about honing was in reference to aluminum cylinders, which are too soft to stand up to the aggressiveness of hones. Jose is talking about rust, rust=iron, which means honing is okay.

If Jan has a problem with honing cast iron, he needs to get the proper stones.

Bill

 

[V6 JOSE]

Hey, wait a minute. If I remember correctly. Jan's admonishment about honing was in reference to aluminum cylinders, which are too soft to stand up to the aggressiveness of hones. Jose is talking about rust, rust=iron, which means honing is okay.

If Jan has a problem with honing cast iron, he needs to get the proper stones.

Bill

Hi Bill,

Rust in a steel bore, can still indicate pitting of the bore. This pitting can be deep, we just don;t know. Honing a steel bore can be done quite effectively, if you use the correct stones, but if the pitting is too deep, you would need to open up the bore enough to get rid of it, and might make the bore too large to let the rubber boot inside seal properly.

$90 is still cheap, for a part that is so important. I really wish you success on the rebuild, so you don't need to do all that work all over again.

Jose

 

[am99ey]

.. the bore is clear, no rust or pitting in the cylindric bore, thats why I try the rebuild path. I will not take a shortcut of safety.
M/C is at the machine shop now. The guy does thorough work, from my judgment. He did a very nice job on my engine already. His domain is old engines, vintage aeroplane engines. Will be back here as soon as I have results.
Andy

 

[am99ey]

Overstretching seal on plunger

Just got it all out on the table, work can begin..
I am not sure if I will overstretch the new seal (9) while squeezing it onto the plunger.
Is there a better solution than rich lubrication (red rubeer grease) while fitting the new seal? It will need quite a bit of force, right?
Will the grease harm function of the hydraulic fluid?
Thanks for an answer of an experienced.
.
btw, MC is worth while to be rebuilt, no other problems occured up to now.

 

[todd reid]

Andy,
Use brake fluid to lubricate the seals and bores before assembly (use the same brake fluid you will use in the system ie Castol LMA, etc). The seals will be a tight fit because they are new. Just take your time, use care, and apply even pressure (no hammers required!). The red grease is intended to go on the dry side of the plunger, under the rubber dust cap to lubricate the push rods travel through the dust cap.
Good Luck!

 

[am99ey]

Todd, thank you for advice. I have finished the job. The seal needed quite a bit of force. Had to use the bench vice to hold the plunger in place while pressing the seal (9) onto the plunger.
The big dust seal I have torn, the sharp edge on the washer cut into the rubber of the small bore. I used the old seal again. Somehow the original material seemed much softer and strechable to me. Bleeding the system; next weekend then...

 

[Bill Blue]

Todd, thank you for advice. I have finished the job. The seal needed quite a bit of force. Had to use the bench vice to hold the plunger in place while pressing the seal (9) onto the plunger.
The big dust seal I have torn, the sharp edge on the washer cut into the rubber of the small bore. I used the old seal again. Somehow the original material seemed much softer and strechable to me. Bleeding the system; next weekend then...

Don't you just hate it when the old stuff is still better than the new? Don't know how many times that kind of thing has happened to me.

Bill