Has anyone not liked the BMW booster upgrade?

[Sodo]

I have two vans:

'90 Westy Syncro, appx 5,200 lbs, 10% bigger wheels, with big brakes, rear discs, garden-variety brake pad materials and age

'87 TinTop Syncro, appx 4300 lbs, 10% bigger wheels, 100% original 54k mile factory brakes - original pads, original shoes

The '87 tintop 100% stock brakes feel MUCH better, less pedal pressure.
There are a lot of details to balance when making brake improvements.
Especially if changing multiple parameters at once.
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'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered original gearbox
....KTMs, GasGas, SPOT mtb

[82westyrabbit]

I installed a BMW brake booster with stock early brakes about four years ago. Just to make it clear, I installed the brake booster because it was cheap and available not because I was looking for a performance upgrade. At first I felt like I had a soft pedal. I had to rebleed the brakes, and I adjusted the rear brakes to get the pedal to feel right. It takes less pedal pressure to stop the van but the pedal is at the same hight as it was before the BMW booster. If the rest of the brake system is not in great shape the new booster will amplify the problem. The speedometer cable is a problem. I get a slight clicking sound from the cable. I am happy with the upgrade if you want to call it that. I have recently installed a big brake kit but have not driven the van since. it will be interesting to see how I feel about the brakes now after I drive it. John

[Christopher Schimke]

[MarkWard]

[ALIKA T3]

[Sodo]

[Gnarlodious]

I guess I would also warn that with this upgrade you are going to see more black dust on your front wheels. Like, a LOT of black dust, I am constantly cleaning it off because I have shiny parts. The dust comes off the brakes hot and electrically charged, so it sticks mightily and on some surfaces actually burns itself into the coating. reporst are that ceramic brake pads being a lighter color make less visible dust particles. Also that a "ceramic wax" on your wheels will prevent such severe sticking. I don't know for real but researched it because of such a lot of black dust on my wheels.
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Vanagon ’83 diesel AAZ w/Giles injection, 5spd 4.57R&P+TBD and a '78 diesel Rabbit

[Sodo]

Interesting re: charged particles sticking….. but how much heat can a tiny particle retain as it passes through the air enroute to your shiny bits?

I wonder if there is an acid etch or something.
It seems to me that it wipes off easily, if you clean it soon, more difficult if you wait.

Wouldn’t the amount of dust depend upon how you use your “increased pedal assistance”?
Braking harder will logically produce more brake dust.
Some might brake the same as before, just pushing less hard on the pedal, and get “same dust.
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'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, SyncroShop pressure-oiled pinion-bearing & GT mainshaft, filtered, cooled gearbox.
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered original gearbox
....KTMs, GasGas, SPOT mtb

[dkoesyncro]

I have had the girling 60 front brakes and BMW booster for apx. 13 yrs. This has been a great feel. This last MogFest I produced some carnage that gave me an opportunity to do a rear disc conversion. I made my own using the Eurovan.

I had a hell of a time bleeding the system so I thought! Soft pedal after soft pedal and nearly 3 qts. of fluid. I convinced myself that my son had over extended the MC and the seals rolled while bleeding . I took apart the MC, cleaned it up and ensured that the seals will ride right. Bench Bled the MC and repeated the whole thing again with a pressure bleeder.

I cracked everything, even the rumored air trapped proportioning valve, joints and junctions. Viola, absolutely sure I’m air free. However, I will report that the pedal feel is softer than it was with rear drums. The e-brake is great though.

As for the MC, years ago and maybe it was even Siekel the Audi 4000 MC was an option. Although fluid dynamics is not my specialty and I believe that larger lines were also needed for those who were going to benefit from this conversion.

[mitch5]

So update, for all those considering doing a swap with booster. Now that I have driven the van I will say it’s not as soft as it was Initially, it stops and has the feel similar to an early 2000’s Subaru. I had some air trapped in the master that the power bleed didn’t get. Cracking open the line then depressing the pedal finally got that.

I will suggest that if you planning to update/convert to discs then I would swap the brakes first without ditching the stock booster. If you like the pedal feel with that then I would keep it. The bmw booster will just decrease the overall force needed but also will change how/when the force is applied.