Guide to VX brake upgrade
#970639 (In Topic #114796)
Guide to VX brake upgrade
I`ve just fitted VX calipers and pads, new discs and a servo and mastercylinder upgrade so thought I`d simplify a few aspects for those who might be thinking of doing the same.
Apologies if its a bit of a repeat of other threads but its now all combined.
You can also see what I`m up to with the car here
The brakes on a Mk 1 Golf are marginal at best.
They lose mechanical efficiency as the servo is placed on the left hand side (designed for left drive cars)
The connection is by a bell crank arm via two pivot boxes.
The pedal pushes on one end and the arm transfers the effort to the servo via pivot levers.
This allows flex and brakes that work but do not inspire confidence.
Although it had GTi discs I decided to upgrade them.
A classic route is to upgrade the servo from a Mk 2 Golf utilising also the Mk 2 master cylinder.
The first stage is to remove the original master cylinder.
9" servo and 22.2" master cylinder from a Mk 2 Golf
The difference in size is clear to see when compared to the original.
The differences when measured from the flanges are clear also.
The next ****** job is to remove the four nuts holding on the servo and the return spring. Awkward to say the least
Then an even worse ****** job is to remove the clevis pin retaining clip buried out of sight. A real PITA job but do-able with patience.
I used a pair of circlip pliers in the end and it was pretty easy after that.
Measure the original servo from the back to the clevis pin centre (130mm on mine)
The differences between the Mk 1 and Mk2 clevis (top) are clear.
The Mk 1 has a hole for the return spring and smaller diameter clevis pin holes.
The Mk 2 servo rod end requires approx 10mm removing from it. Here you can see the Mk 1 clevis fitted and the threads protruding.
Although it appears long, it isn't its just the camera angle but the thread has been cut down and the Mk 2 servo
dimension with the Mk1 clevis fitted is now 130mm. Perfect.
All back in and bolted up and the Mk 2 master cylinder and reservoir installed.
It is a tight fit but the header tank and gear linkage miss (just) without issues at all.
The master cylinder had only two outlets and this blanking plug centre had been filled flush with hard compound (I assume by the factory)
I preferred three outlets so I scraped out the compound and found it was an allen key and when undone I had another outlet.
I removed the old caliper, carrier, disc and backing plate. Leave the backing plate on if its a regular road user/daily driver.
I do not want to retain the plate because it restricts air flow to the inside of the disc which is where discs cool from - in to out.
New Brembo disc (from GSF) fitted. 256mm as against the 239mm original.
Not a lot bigger but a better mechanical advantage nonetheless and with bigger pads will stop more efficiently (I hope)
Vauxhall Vectra GSi calipers and pads. New from e-bay. The carriers have the same hole centres as the golf hub (which is nice)
You can see how much bigger the Vectra calipers are. The piston diameter is the same as the Golf (50mm).
The greater mechanical advantage offered by the larger pad area, master cylinder and servo should mean better brakes for the same or slightly less effort.
Bolted up with shoulder bolts that required a washer to centre the carrier.
Disc caliper and pads fitted
New brake hose fitted (from a Vauxhall B type Carlton)
Note the square `banjo` type fitting. The silver mount collar is clamped to the hose and is just too near
the end of the hose to use on the FK coilover strut body. I will cut off and re-weld the tab in a better position when I get more time.
The mess is simply `Coppergrease` designed to prevent further corrosion on the clip until its all sorted properly.
Note: always block off openings in pipes until needed or connected. I use a bit of masking tape.
You will need to use a male to male bulkhead fitting which works with the original VW mount and clip.
Like this one.
When using the Vauxhall type square `banjo` bolt connection ensure you use new washers.
The original copper washers (top) came with the `banjo` bolt acquired from a scrap yard.
You can see the sealing ridges machined into the caliper have been impressed upon the washers.
The new washers are from a VX dealer and are aluminium and cost about 10p each so buy plenty.
Other side done. All I need to do now is connect new pipes to the master cylinder.
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