Disk brake conversion

[chubbub2005]

I've just bought a CSP front disk brake conversion kit and am not sure about changing the master cylinder to a disk brake type.
I got the kit from machine 7 who have said it's not necessary according to CSP, rang CSP to make sure and the guy said he was "pretty" sure it wasn't needed which wasn't much help.
The info in the instructions for the kit says don't run using a drum brake cylinder but just gives info on an adaptor kit and cylinder for a split.
Was going to fit the kit without changing cylinder but now not so sure as my first outing will be a 700 mile round trip and I wont have time to order a m/c and fit it before I go.
1970 Dormy on 14" steel wheels.
Any opinions?

 

[slammedkustom]

you do need to change the MC if its a drum one, otherwise the calipers will drag and warp the disc.
drum MCs have a higher residual pressure than disc ones as the wheel cylinders are almost pressurised ready to work.

you wil also need the MC fitting kit, try creative enginnering as they are about half the price of the other suppliers on these :wink:

 

[Justin & Muttley]

^^^WHS

 

[chubbub2005]

Thanks for the replies.
Thats what it says in the instructions for the kit but when I rang CSP
they said it's ok without.
I'm gonna have to fit one or I suppose it'll be one of those things thats constantly at the back of my mind nagging. (like the wife )

 

[slammedkustom]

its a lot cheaper to change the MC than get new CSP disc rotors.
and your'll know its a new part :wink:

 

[currylager]

Just do the conversion after the 700 mile trip and then there is no stress and you can tinker to your hearts content. Sometimes if its running OK, leave well alone. Those pre expedition tweaks have a nasty habit of going wrong :wink:

 

[chubbub2005]

Master cylinder and fitting kit not due for delivery for over a week so I've not got the choice but I know what you mean.

 

[kevdonlon]

havent changed the master cylinder on mine,no problems at all

 

[maddog]

If you know its the original m/cylinder then yes id change it - if its had one replaced at some time you should be ok.

I asked around before i did my conversion. I fitted a m/cylinder 10 yrs ago. Apparently most after market ones are ok and wont keep the pressure on the calipers.

Mines been fine and ive now covered 1200 miles in it.

Just make sure you have NO play in the wheel bearings. Normally a little play in taper roller bearings is ok but ive found that with even a really small amount of play, the bottom of the brake pads rub on the discs (where they shouldnt do!) causing slight grinding noise.

 

[faux]

What Master Cylinder did you fit?

Mine is a 69 bus.

 

[faux]

I have looked into this over the past couple of days and still don't have a concrete answer. It seems that I should be fitting a non servo M/C, which would go on a non servo'd front disc brake bay...8/70>

Can anyone confirm this to be right?

 

[chubbub2005]

Just received master cylinder and fitting kit from creative engineering and it's for a bus up to 1967 doh!
Am I right in assuming I need a non servo master cylinder from a 70 to 79 van.
And is this a straight swop ie. can I reuse the reservoir and just bolt it on.

 

[67 BAY]

Yes just bolt it on and use original res,you may needto alter some brake pipes.

 

[Fraggle]

Well then......

I've done the csp 14" disk conversion on my 68 and changed the master over to a late disk brake master as contacted CSP direct via email and they said not to use the original.

Can't say I'm that impressed as the pedals rock hard and you need to push it just as hard as before.

Anyone else done this or solved this problem???

 

[giraffeinbath]

an't say I'm that impressed as the pedals rock hard and you need to push it just as hard as before.

Would I be right in thinking that without a servo the disks would be just as hard as they were previously with drums?

I was wondering whether the remote servo offered for splits by Creative Engineering could be used on a bay, not sure how the 'remote' nature of it works though. Seen the advert in the mags, nothing on their website about it though.

 

[faux]

I have just done this to my 69 bus. I changed the MC to a later non servo(71>) MC £30 from GSF part no: 65230. I did have to extend one brake line by 3".

It seems to be working well at the moment

 

[aggri1]

an't say I'm that impressed as the pedals rock hard and you need to push it just as hard as before.

Would I be right in thinking that without a servo the disks would be just as hard as they were previously with drums?

Unless you attached the vacuum booster line then yes the pedal will be quite stiff. Stopping my '74 (boosted discs) when the engine isn't running requires harder pedal pushing than either my '69 or '67, which are both non-boosted drums.

With the engine running and the vacuum line booster working it's of course MUCH nicer.

Cheers, A.

 

[Fraggle]

I contacted CSP at the weekend and this is there reply-

Hi there,

first of all, disc brakes must be used with a matching disc brake master cylinder. Original units can't be used because of their residual pressure valve.

So if the car is converted from drum to disc and the master cylinder is still original it must be changed to a disc brake master cylinder. On early bay window models it can be changed to late model 73-79 master cylinder.

Normally late buses are equipped with a servo unit and a larger master cylinder diameter. In 99% of all installations this master cylinder is used along the CSP disc brake conversion.

CSP is currently not offering a matching installation kit for the master cylinder and reservoir as the location of the reservoir is still unsolved with CSP. This is caused by the simple fact that we do not have an early bay window to make some test fitments.

The larger servo type master cylinder will cause a very stiff pedal pressure if not run under engine vacuum. If the pedal pressure is to stiff for the customers choice, we offer a smaller m/c (611 021 211-14). This unit holds a 22mm master cylinder piston and is currently only available for pre 67 buses as the reservoir location is not yet solved on early bays.



So we know the size and type of master cylinder to use on early bays but we are not sure about the ideal position of the fluid reservoir.



We need to have some customers feedback in this to set up a part kit for early bays.

Who is willing to help?



Thomas Kelm

CSP

 

[Justin & Muttley]

...This is caused by the simple fact that we do not have an early bay window to make some test fitments...

That sounds a bit lame to me - they're not seriously trying to tell you that they can't lay their hands on an early bay? :shock:

 

[Fraggle]

I'm more 'not well chuffed' at the fact that they are marketing / selling a bolt straight on kit at a whacking £700 that isn't properly 'researched' yet!!

For my wonga I wanted proper brakes and not to have to experiment / cock about with different master cylinders etc.

These kits are being sold over here but reputable companies as a straight bolt on affair with no need to change master cylinders. I know this as I phoned over 3 dealers who all said the same thing.

All I know is my brake pedal's pretty hard and it could be better. I had the 15" kit on my splitty and that worked well so I know that they ain't performing as well.

:roll: