What other masterpump and servo for MK1 brake upgrade?

Hi all,

I want to upgrade the masterpump and servo on my MK1 GTI.

There is much info on this topic, but they all relate to a MKII 16v servo.
Unfortunately this is very hard to find here.

I was wondering, maybe there are more recent car's to take a servo of?

Does anybody have some info on this, or can you show me topics on this?

By the way, why arn't people taking MK1 convertible brake parts? As this is a more recent car I thought this would also be a better servo,  or is it as bad as the MK1?

Thanks!

any mk2 golf 1.8 will do for4 the servo, they're all 9". also most coprrado and passat b3/4.

for the master cylinder buy this new, look for a mk2/3/corrado/passat/etc 22mm one, common to lots of models.

our old 2000 1.4 seat ibiza had the 22mm master cylinder for example

Hi John,

Thanks for your reply, that makes it a lot more clearer to me!  

Just wondering, why won't a booster of a MK3, or more recent won't do? Are they physically too big maybe?

Problem is, I live in Belgium, and MK2 parts become hard to score here, MK3 and recent is a bit easier …  

the mk3 one is the same bolt pattern at the back, and most will take mk2 brake master cylinders (abs ones often different) but it uses a ball end pin to attach to the pedal. you can cut it off and tap a thread up it to convert to mk1/2 fit

Ok, now that's good news!  
I'll just cut it of and tap new thread then!

As you are clearly an expert to this matter
I'm just curious … Do you know why the braking improves when upgrading your master cylinder?

I always assumed it was the servo that helps on giving you more braking power with less effort, and therefore is important in good braking power and that the master cylinder is "just" a pump that pushes the oil with no much improvement possible … ?

the servo is what improves the force to the brakes, the master cylinder size just changes the distance the pedal has to travel for a given pedal input. a combo of both is good for the mk1 which are known for a long pedal and can benefit from a bit more force. Plus the main reason we do it is we have the cross bar linkage to join the pedal on the right side of the car, to the master cylinder and servo on the left side!  LHD cars dont have any of that and so generally there is no problem

though if all the braking system components are good the mk1 system is fine really, many of those who complain are running old fluid with worn and/or badly adjusted components on the mk2 gofl the 22mm master cylinder is only required when you fit 256/280mm calipers which use larger pistons, and so you need to move more fluid.  if you dont change the MC with the brakes the pedal travel increases vs the 20mm mc + 239mm brakes. if you keep 239mm brakes then the 20mm master is fine

If only everyone was able to give such clear and detailed explanations …

Great info thanks John !!

     

you're very welcome

Resurrecting Post

I have seen multiple new threads where people are using the following in mk1/mk2 applications.
What other Servos and MC can be used with description of Modifications? doesnt have to be VAG


SERVO
Any VW mk2 Era 1.8 Servo = 9"
MR2 Servo - modify mounting points and bar length for Clevis pin
Mk3 9"- modify thread length, tap and affix clevis pin


MC
-Stubby mk1 ford Focus
-Stubby Seat Ibiza
-mk2 22mm MC in conjunction with mk2 servo

My friend is uprating my brakes fitting the mk2 servo and m/c. He is asking how do you get the rear brake lights to work because its a different set up please?

What rear brakes are you going with?

Just make a bracket at the break pedal with a push switch connected to it. This is how I did it. Works like a charm

Verstuurd vanaf mijn SM-G935F met Tapatalk

Yep, early styles had the switches on the servos, the latter ones had an electrical switch.

rubjonny said

What rear brakes are you going with?

Sorry didn't see this question😬Standard drums

Hopefully this will be the last question for now. Not sure if you know but do i need to upgrade the brake fluid reservoir on my mk1 for the 16v upgrade?

ok so as above then, mount a pedal switch or plumb in a pair of T pieces nicked off a mk2/3 golf.

you need the mk2 fluid reservoir to go with the master cylinder, but it can also be found on mk3 golf, 6n polo, ibiza up to 2001, caddy van of similar age etc so not hard to get one.

rubjonny said

the servo is what improves the force to the brakes, the master cylinder size just changes the distance the pedal has to travel for a given pedal input. a combo of both is good for the mk1 which are known for a long pedal and can benefit from a bit more force. Plus the main reason we do it is we have the cross bar linkage to join the pedal on the right side of the car, to the master cylinder and servo on the left side!  LHD cars dont have any of that and so generally there is no problem

though if all the braking system components are good the mk1 system is fine really, many of those who complain are running old fluid with worn and/or badly adjusted components on the mk2 gofl the 22mm master cylinder is only required when you fit 256/280mm calipers which use larger pistons, and so you need to move more fluid.  if you dont change the MC with the brakes the pedal travel increases vs the 20mm mc + 239mm brakes. if you keep 239mm brakes then the 20mm master is fine

Some great info here.

I have a question…

What would be the benefit of a simple 9 inch servo upgrade on the standard linkage bar and GTI 20mm MC & reservoir? Is it worthwhile?

I've used 16V Servos and 22mm MC in the past with 239mm front and mk2 rear discs to very good effect. 

I'm conscious that there's a fair bit of fiddling with brake lines and switches to fit another MC in an early GTI, and it's also quite a visual change from standard, where fitting just a slightly larger servo goes almost unnoticed.

you cant use a mk1 master cylinder on a mk2 servo thats the trouble, as its different round the back. the later cabrio/scirocco servo I think is same fit as mk2 and slightly larger so there is that.

on my 83 cabrio I went with 9" and 16v master, then because I had rear discs I could delete the residual pressure valves in the rear lines near the bottom of the engine bay. In their place I fitted a pair of mk2/3 golf T pieces so I could put my brake switches in, and keep all the standard mk1 hard lines. Alternatively you can fit a pedal mounted brake switch like late cab/rocco had and again keep original pipes in the bay

Cheers. The main issue is the flex in the brace bar linkage and the bulkhead. I'm sure that simply upgrading these to the Autocavan Superbrake conversion fixed the majority of the issue.
I wonder if you could stiffen the bulkhead, or alter the ratio of the pivot points.
Also, would it be possible to bore the master cylinder slightly?
I'd rather work with improving what's there, but without any noticeable visual alterations.

I've heard of people maybe using the pug one? tbh I didnt notice much flex on my cab, I guess because the servo was beefier so I didnt need to pus hthe pedal so hard to get the desired effect…

it wouldn't take much to beef up the existing bar, something as simple as a bit of U shaped steel between the 2 mounting points in the engine bay the bar assembly can slot into

Not a reply but a question. All you experienced folk. 

I have read up all I can find on upgrading the brakes on my 1993 mk1 clipper. Standard 239 mm front disk and rear drums. 
I have acquired a 9" mk2 16v servo plus a 22. mm master cylinder and am ready to reinstall.
 My question is regarding the two rear brake resistor valves screwed into the original master cylinder. Part numbers thereon:
1292G on one and 127G2 and a 2 on its side on the other   
Other markings are 3 arrow down and 35. Like 3v35. 

After significant searching, I have been unable to find anything with similar part numbers but have seen mention of mk 1 rear brake restrictor valves needed for 19.8 mm master cylinders. 
I have also seen mention of restrictors being required when upgrading to rear disks, to stop locking up. As at present, still using drums but upsizing to 22.2 cylinder do I reuse the restrictors, or not?

Another point for anyone attempting to remove the Clovis pin on the linkage, I had nowhere seen mention of the type of locking mechanism spring clip on the pin. 
This needs to be sprung open to remove, easy if you know what it is but being so well hidden and working by touch, this knowledge may help someone. To replace, pushing a small Allen key in to keep it open helps considerably, easy to pull out after fitting. 
Another question though is, where is the felt washer supposed to be fitted. 

Paul.