Dual 7" Servo - Page 18

Mike · #**341** 13th January 2012, 19:59

My m/c is for the Ford Sierra and has the same no. on it: and has the Sierra reservoir mounted directly on top.
Mike

Quote:

Originally Posted by jeremy

From memory I am using a ford m.c. -think it is this as it is mounted at an angle with remote reservoir on metro servo. looking at it in-situ it has the number 383059 on it

Sorton · #**342** 13th January 2012, 22:06

Looking at my old (E30 OE) m/c I find that the full travel of the shaft is 13mm and it would therefore be possible to cut 15mm off this shaft without effect on the seal. However, the circlip is tamper-proof so I have not been able to look inside.

On my new (after market) m/c, on the other hand, the shaft can be pushed in its full length. Similarly, the dual servo shaft certainly travels more than 13mm. The servo output shaft would also need to be considerably extended if the BMW m/c was used.

It would seem possible to bodge the two together but in my view it would look horrible and would be mechanically very suspect. Personally, I do not think it deserves further consideration.

The BMW cylinder seems to be 25mm inside diameter measured at the circlip. I wonder how critical this diameter is for pedal feel?

It occurs to me that, although the Ford m/c is the obvious answer, there must be an m/c out there that has the same stud pattern as the servo and would fit without any spacing? I will have to keep looking!

Changing the subject slightly, has anyone looked closely at the pictures of the new factory built M3 Sportster in Complete Kit Car Magazine. There is no sign of a servo or m/c in the normal place so I assume Mark has gone for a remote set up. I think the servo may be in the battery tray. Also, the exhaust is interesting with silencers down each side and rear tail pipes. I look forward to a close examination.

morris · #**343** 13th January 2012, 23:14

yep, Mark put the standard BMW servo in the battery tray with a linkage through from the pedal box. I remember asking him when I saw it about a year ago if that was the way to set things up now and and he said it was so complicated to to get right that he'd not do it in future

denniswpearce · #**344** 14th January 2012, 12:55

Yes ,you are right Ian. When I was at the Exeter show Mark said the same then. That car is a one off as far as the servo is concerned, so don,t go down that route.

denniswpearce · #**345** 14th January 2012, 16:19

Ian, your cunning plan looks interesting but I would prefer the M/C to be fitted flush onto the plate, with all its mounting surface in contact with the back plate. There is a lot pressure there and I would always wonder if the fixing would move. Having said that I am not a mechanical engineer.
Be interesting to hear other peoples opinion on your solution

morris · #**346** 14th January 2012, 17:20

yep, I quite agree that I'd prefer it flush too. If there wasn't this question mark over what the right part number is for the ford cylinder I'd just be ordering one of those and washing my hands of the BMW part but I don't want to waste money through trial and error finding the right part.

With the setup shown in the photo I wouldn't be happy but with a good brace at 4 points rather than 2 I think it would be solid. It's worth remembering that the forces involved in pushing the M/C are nothing in comparison to the tensile strength of a bog standard bolt so as long as everything is straight and you're not pushing the M/C at an angle, it will be mechanically sound. If I take 10mm off the plunger then the M/C will sit flush to the 5mm thick adapter meaning the forces will be spread nice and even

The question in my mind is all about the air tight seal as if that is an issue then it's a non-starter.

Mike · #**347** 14th January 2012, 18:18

Ian

Please do not take this as suppotrting your idea to cut and carve your BMW MC, but there is not an issue with maintaining the seal. The MBM servo is self sealed. We know this from GOOs trial with my first adaptor plate which had a slight bow in it.

I have a pattern MC for a Ford and will try to find out on Monday where I sourced it from and if they are freely available.

Mike

Quote:

Originally Posted by morris

yep, I quite agree that I'd prefer it flush too. If there wasn't this question mark over what the right part number is for the ford cylinder I'd just be ordering one of those and washing my hands of the BMW part but I don't want to waste money through trial and error finding the right part.

With the setup shown in the photo I wouldn't be happy but with a good brace at 4 points rather than 2 I think it would be solid. It's worth remembering that the forces involved in pushing the M/C are nothing in comparison to the tensile strength of a bog standard bolt so as long as everything is straight and you're not pushing the M/C at an angle, it will be mechanically sound. If I take 10mm off the plunger then the M/C will sit flush to the 5mm thick adapter meaning the forces will be spread nice and even

The question in my mind is all about the air tight seal as if that is an issue then it's a non-starter.

Mike · #**348** 14th January 2012, 18:44

All
I have just had a call from Alan Hogg to say he has fitted his servo kit in his Cabrio (BMW M20) today, and is thrilled with transformation of his brakes. "A revalation" to use his own words. He has his car on the road all year around, and has taken it for a proper drive, and says the pedal has much more feel to it, and that if he wanted to, felt he could have locked his wheels up. A real success.
I am delighted with his call on many levels. Obviously with 20 people buying the kit I felt a real sense of responsibility for ensuring you were not disappointed! So to have someone be so pleased that he wanted to give me a call to say thank you personally is very satisfying. He found the kit very easy to fit, and was pleased with its quality and simplicity. He drilled two holes, added a counter sink at the rear, and fitted it.
I am also pleased because Alan's Cabrio is Ford based and he has the same Cosworth disc front & rear disc set up with a Ford MC that I have selected. So all being well my brakes should work.
I tghink the moral of the story is that with a Ford master cylinder the conversion is simple straight forward, and it works.

I do hope all of you with BMW master cylinders are able to find a safe workable solution and that it works just as well for you. Jason, GOO, has PM'd me that he is fitting his servo today, so hopefully he will be able to elaborate a little more on the success of the kit in a BMW based Sportster.

Good luck to all
Mike

morris · #**349** 14th January 2012, 18:45

Hi Mike, I'm only going to mod the BMW M/C if no other M/C can be identified. I fully take on board what's already been said about the potential to have a failure inside the M/C if the plunger is chopped so really just exploring alternatives. My car's a long way from being on the road so it's silly to start bashing things up when a bit of patience will get a better result.

Hopefully you'll get a positive ID on it on Monday.

cheers
Ian

cabrioman · #**350** 14th January 2012, 20:16

Mike

Do you know if Alan is running the ford master cylinder with a directly mounted master cylinder?

John

GreatOldOne · #**351** 15th January 2012, 07:34

I started fitting the servo yesterday:

It's all been taken apart again so I could paint the adaptor plate - I'll bolt in permanently today. But everything fits!

denniswpearce · #**352** 15th January 2012, 08:55

Well done Jason and looks good...................but ??????,
is it an optical illusion or does the end of the M/C foul the side panel or indeed the bonnet ?

GreatOldOne · #**353** 15th January 2012, 15:42

No, no fouling of the side panel or bonnet - everything shuts as it should.

I've completed the install today. I used the output rod that I turned in engineering class - it's a bit of mild steel to these dimensions:

It replaces the one that came with the servo - I reused the knurled locking ring though.

I wound it out and kept trying the master cylinder with the adaptor plate bolted on in place until I could make plate and the face of the servo touch with no resistance on the cylinder.

Then it was just a case of running new fluid feed lines (the old ones where two short), putting the heat shielding back on and voila:

I haven't had a chance to road test yet, as the dashboard and centre console are out whilst I wire up my starter button.

peterux · #**354** 17th January 2012, 16:54

Does anybody know if it matters whether the front brake pipes come off the cylinder outlets nearest the servo or not.

The BMW M/C has the front brakes nearest the servo and the rear brake line off the furthest. The 'Ford' types seem to be the other way round?

I can't think of a good reason why it matters but wonder if anyone knows better?

Mike · #**355** 17th January 2012, 18:45

I think we are half way to finding out which brake master cylinder to go for. John at Kit-fit Newark (very knowledgable about Fords) has identified it is Bendix, and not Lucas Girling, by the fact that the hole centres are on a 70mm pcd, and the studs are 8mm not 10mm.

So you need to be looking for a bendix m/c.

Have a look at this site - for reference only, as the prices seem horrific! The master cylinder I have looks like this one:

Note two pipes exit to the left (to wards the engine), and the third exits vertically downwards: this is for a Right Hand Drive vehicle. Whilst this is not essential, exiting to the engine will avoid the issues GOO had with them exiting to the side panel,(his is originally for a Left hand Drive vehicle). He has a remote reservoir, and was able to rotate the m/c so that his pipes missed the side panel. For those of you wishing to fit a reservoir directly to the m/c, it has to sit horizontally, therefore the pipes must exit towards the engine. (There is one which exits vertically down).

John is going to make a few phone calls tomorrow to see if he can source this specification m/c, and see what price he can come up with. I'll let you know what he comes back with.

Regards
Mike

Mike · #**356** 17th January 2012, 19:03

Peter

I do not know the answer, but an educated guess would be they are all the same. The Ford m/c has 22 stamped on the side which refers to the bore size - which suggests there is only one size.
Also the Sierra front wheels have their own brake pipe each, and so the bore must be the same for each.
I do not know abou which way around to fit them, but again would suggest they are all the same.
If the bore sizes were different the pressure generated would be quite different too, which would not be desirable. This is usually controlled by a brake bias valve instead.

Quote:

Originally Posted by peterux

Does anybody know if it matters whether the front brake pipes come off the cylinder outlets nearest the servo or not.

The BMW M/C has the front brakes nearest the servo and the rear brake line off the furthest. The 'Ford' types seem to be the other way round?

I can't think of a good reason why it matters but wonder if anyone knows better?

cabrioman · #**357** 17th January 2012, 19:06

Yep that looks exactly like the one I have Mike, I always thought it was Girling so it shows what I know !

Thanks for dropping off the kit yesterday, much appreciated.

On the discussion we had around your diff, you may want to take a look here

http://www.super7thheaven.co.uk/Sier...r_Differential

lots of info and it states the standard and koala type back plates are interchangable so you should be able to go with your own diff and use the other style backplate to alter the diff mount (assuming their info is correct)

John

Mike · #**358** 17th January 2012, 19:15

Hi John

Snap - I thought mine was a Girling too!

Thanks for the Diff site lead - the problem is, the changeable back plate is for the 7.5" diff and of course I have the 7". Doh!
I am certain I will have to change the diff support on mine though due to the wind up. I may choose to make myself a bracket which attaches to my 7" diff but mimics the koala double stiffer mounting.

(The clevis is in the post for tomorrow collection)

Cheers
Mike

Quote:

Originally Posted by cabrioman

Yep that looks exactly like the one I have Mike, I always thought it was Girling so it shows what I know !

Thanks for dropping off the kit yesterday, much appreciated.

On the discussion we had around your diff, you may want to take a look here

http://www.super7thheaven.co.uk/Sier...r_Differential

lots of info and it states the standard and koala type back plates are interchangable so you should be able to go with your own diff and use the other style backplate to alter the diff mount (assuming their info is correct)

John

cabrioman · #**359** 17th January 2012, 19:23

Oh I forgot you had the 7" diff, maybe a poly bush might be worth trying if you can find one at half sensible money.

Thanks for posting the clevis.

John

denniswpearce · #**360** 17th January 2012, 20:45

Mike, you wrote "The Ford m/c has 22 stamped on the side".
Not having installed the m/c on my Sportster, I am not sure which one is fitted to mine. It looks identical to Jasons pic but I can only find a small mark on the side nearest the engine and it may well be the number 22 ( will have to get a mirror as it is mostly hidden )
Question for you Mike is " Is the number 22 on the Ford m/c on the side nearest the engine as Jasons pic above please.
Dennis