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Sat Feb 27, 2010 6:57 pm

To improve my brakes, I have installed Audi G60 brake calipers and vented rotors on the front and vented disc brakes on the back but I thought that I could improve the brake system even more by installing a bigger brake booster.

After scrounging through a lot of wrecking yards and looking at brake boosters I found a 10" booster that will fit the Vanagon without any major modifications.
The original Vanagon brake booster has a 9" diameter so an upgrade to a 10" means that it is like putting about 20 percent more force on the pedal with the same effort.

The brake booster came from a E30 (3) series BMW, which is easy to find in wrecking yards, made from 1982---- 1990, and until 1993 for the convertible.

I test fitted the booster on a spare set of pedals first to see if it fitted.

The BMW unit is on the left.

To make it fit, a 1/4" piece has to be cut off the threaded rod, then the original clevis from a Vanagon has to be drilled out and tapped to M10x1.5 (drill with a11/32" drill) and mounted onto the threaded rod.
Adjust the length of the rod to 111,5 MM or 4 3/8" from booster mounting face to the center of the clevis. (see Bentley page 46.10)

The BMW clevis is on the right, the pin doesn't fit.

Installation.

I had already replaced my heater core and did not want to take the whole dashboard out again so I just took the instrument panel out, drained all the brake fluid out of the reservoir and unbolted the master cylinder, making sure that no brake fluid was spilled.

The hard part was to take out the two small brackets from the steering column mount to the mount under the windshield. I ended up bending a 10 mm wrench to get the angle right.

Next I had to unbolt the clutch master cylinder, the aluminum pedal frame, the vacuum line and lift the frame up a bit in order to get the pivot pin out of the clevis and removed the booster.

Since I was in there, I removed the clutch pedal and checked and lubricated the pivot pin to the clutch master cylinder, I left the brake pedal in place.

Next was to put it all back in reverse order and bleed the brakes.

I have not tested it on the road yet, I will have to have to go through a vehicle inspection first in March in order to drive it on the road but it feels better than before.

Herman

Sat Feb 27, 2010 7:05 pm

That's sweet! I had been wondering about the possibility of doing this. Please let us know how it works!!

Sat Feb 27, 2010 7:05 pm

why do you need a vehicle inspection?

Sat Feb 27, 2010 7:10 pm

Hey Gordy, it is a US vehicle.

Cheers Herman

Sat Feb 27, 2010 7:14 pm

In the syncro yahoo group this came up a little while ago. Florian got a part from germany that is supposed to work BMW part# 34331157983 http://autos.groups.yahoo.com/group/Syncro/message/44354
I cannot find one on this side of the pond. It is good know that there is a US version that might work. 8)
Is there a part number on yours?

Sat Feb 27, 2010 7:29 pm

Hey that's a really useful write up and pics. Even just to show how the pedals/booster etc can be R&R'd with dash left in place.

Neil.

Sat Feb 27, 2010 9:12 pm

I have a bigger one that is from europe it was sent over with my rear brake set up. Fit right in are so I was told I did not do that job.
Even with the rear brakes not working the van stops great.

Sat Feb 27, 2010 11:10 pm

Are there any downsides to a bigger brake booster?

Sun Feb 28, 2010 1:28 am

wbx wrote: Are there any downsides to a bigger brake booster?
Sure.

With stock brakes you could smoke them, lock them up and maybe blow cylinders.

People have been known to hurt themselves with too much brakes, too easy to apply.

Big brakes don't seem to need more help, though for most applications, but with all the lifting, bigger wheels and bigger engines going into the vans, a little easier pedal may help.

Sun Feb 28, 2010 7:40 am

I have used this with big brake upgrades front and rear.
Yes, the parts need to be sourced from Europe.

dylan

Sun Feb 28, 2010 7:57 am

wbx wrote: Are there any downsides to a bigger brake booster?

It really comes down to brake modulation/sensitivity. With more booster pressure comes less leg effort for a given amount of braking pressure. If the booster pressure is too great, it will be hard to "feel" what the brakes are doing and will therefore be easier to apply too much brake when it's not wanted/needed.

The larger booster will not give you any more ultimate stopping power out of an otherwise same braking system. It will increase the initial pressure that is applied to the master cylinder and that increased initial pressure means that you can reach a specified brake system pressure slightly sooner in the pedal travel and with less effort than with the smaller booster. Ultimately, the same peak pressure can be reached with the small booster, it just takes more foot pressure to do so.

Of the people that I know who have installed this larger booster, all have had modified braking systems and all have liked the upgrade. I don't know anyone who has made the change to a stock braking system. I have an Oettinger booster (basically the same as the USA based BMW unit) here that I have been planning to install on my big braked van. Maybe I should install it on the stock van first just to see what it feels like. My guess is that on the early van (stock early style brakes), the upgrade might be worthwhile, but on the later vans that have the larger caliper pistons (stock later style brakes), the larger booster might be too much. That's only a rough guess though.

Sun Feb 28, 2010 8:26 am

insyncro wrote: Yes, the parts need to be sourced from Europe.

dylan
The BMW booster that Syncrodoka lists above is available in the US, used, for about $50 thru recyclers.

Now that the cat is out of the bag on this, they may dry up.. :lol:
But there were a heck of a lot of 3 series BMWs that used this ATE booster.

The timing of this thread is amazing.. I have two boosters arrving via UPS early next week. Mine will be coupled with G60s and 288mm disks inside 16s and 29" tires. Additional pedal will be appreciated.
The other goes on a van with VC big brake kit, (I think)

Thanks itzdshtz for the photos! Very helpful.
Given that you did not pull the dash, how many wrenching hours went into this project?
I dread the dash... but I hear its not as bad as some make it out to be.
Good to know it can go in either way.

Sun Feb 28, 2010 8:51 am

Sorry, NEW parts can be sourced from Europe.

df

Sun Feb 28, 2010 8:55 am

insyncro wrote: Sorry, NEW parts can be sourced from Europe.

df

Just to clarify, new BMW boosters are availble through the US BMW dealers as well. In other words, a person does not have to have a European contact to order a new BMW booster.

Sun Feb 28, 2010 10:39 am

I missed the boat on this one.
I have used a larger master cylinder, not booster.
The system was larger up front and disc in rear.
I did all new plumbing.

The part I used was from a Eurospec car that needed a small mod.

My bad.

dylan

Sun Feb 28, 2010 10:47 am

I have tried the EU number through many online dealers in the US and they don't recognize it. I guess that one would have to walk into a dealer and get a price quote.
Yanking one out of the many US spec. 3 series BMW's in the junk yard seems a lot cheaper though. The brake booster is one part that seems to last.
I want to put one on my trail toy with 29" tires with the audi G60 front brakes- still looking for a good rear disk brake with a E brake that works well.
Thanks for the writeup itzdshtz

Sun Feb 28, 2010 11:19 am

E30s came with two different boosters:
ATE 34331157416
GIRLING 34331157908

Sun Feb 28, 2010 12:04 pm

Thanks guys.
It took me about 4 hours to install it after I did the modification on the rod and clevis, so I still think you save some time over pulling the whole dash out. This included pulling the clutch pedal out for a check up.
The small brackets on top took some time, I glued the washers onto the 6 mm bolts with crazy glue and then I could just slide them in place with one finger.
You really have to watch that you don't get a bunch of wires in between the pedal frame and the body.

You can buy a new or rebuild unit here:

http://www.car-stuff.com/store/?N=9709+4294963685+1580+11921+9177

Even the Gowesty discount site shows one:

http://www.gowestyautoparts.com/OEM/viewProducts.a...rake+Servo

Herman

Mon Mar 01, 2010 5:23 am

I have done this install coupled with G60 calipers and I think it's one of the best upgrades available.

Mon Mar 01, 2010 6:48 am

interesting, although I would go with a larger master cylinder over a larger booster. A larger booster will make it easier to depress the pedal, but not necessarily give you any more braking "power".