Dead booster? no power brakes

[fronton]

I did a s38b36 swap and due to the location and size of the intake plenum, like everyone else, I had to use a smaller diameter brake booster. I went with the iX booster and MC. Swap went great and brakes worked perfectly for a couple hundred miles until I took it to BMW specialty shop for a tire change and alignment. When I got it back, I had no brake assist.

The shop said they didn't touch anything booster or brake related and it was working when they test drove it. They say my booster must have just failed when I started to drive it away. Very unlikely timing in my opinion but regardless of fault, they took zero responsibility and I'm left to figure it out.

On to my question: Other than replacing the booster which is a large hassle, is there anything else I can test that may have cause the assist failure? There is no hissing noise or vacuum leak that I can hear or feel, idle is fine, everything else is normal, just REALLY hard brake pedals that aren't confidence inspiring. I drove the 10 miles home ok with lots of distance to slow down but I won't drive again until its sorted.

My ABS light is on as well as brake lining light since my sensors are not all hooked up but I don't think that is related to the assist failure.

Like many others, before when the brakes works, there was an occasional hissing noise coming from a faulty connection on the booster where the main vacuum line connects. Now there is no hissing.

Thanks

[Mr.SWISS]

Bladder is blown out, makes driving scary to say the least, I drove like that for almost a year.

[fronton]

Bladder is blown out, makes driving scary to say the least, I drove like that for almost a year.

Wow, was it worse than driving with a proper power steering delete? I feel like it must be because even with my foot full pressed on the pedal, on a steep downhill, I can barely slow to a stop... from just a couple miles an hour.

Could it possibly be the MC or are you certain it is the bladder?

[Mr.SWISS]

Wow, was it worse than driving with a proper power steering delete? I feel like it must be because even with my foot full pressed on the pedal, on a steep downhill, I can barely slow to a stop... from just a couple miles an hour.

Could it possibly be the MC or are you certain it is the bladder?

Well, if you have no power brakes, and a massive vacuum leak it's a strong muthafuckin possibility your booster has shit the bed.

[nrubenstein]

Did you install a check valve? I had intermittent loss of brake boost issues on my swap until I installed a check valve on my booster. It was kind of weird.

When the booster fails, either the booster is bad, or the vacuum system is bad. The MC doesn't influence this unless it's leaking brake fluid into the booster (in which case both could be bad).

[fronton]

I do not have a check valve. No fluid ever leaked. I think my booster is dead because its not intermittent, just done assisting. :( thanks

[Mr.SWISS]

I robbed a check valve from an eta in the sally. I suggest you do the same when you replace your booster.


Hey! Why not take the chance to try an A4 1.8T or an E32/ix booster?

I love the ix booster and e32 master feel. Not as grabby/touchy, but doesn't need much force to engage ABS.

[etxxz]

Did you install a check valve?

x2

just did some work and put it backassward. since u don't have one i guess its just your booster - bad luck there pal. Highly suggest one, give you that one last emergency stop when your booster fails or vacuum goes... plus they are either cheap.. or free as mr.swiss and I have found simiar sources.

[fronton]

I robbed a check valve from an eta in the sally. I suggest you do the same when you replace your booster.


Hey! Why not take the chance to try an A4 1.8T or an E32/ix booster?

I love the ix booster and e32 master feel. Not as grabby/touchy, but doesn't need much force to engage ABS.

I had the iX booster, it is the one that failed. Where does the check valve go, between the booster and the engine I assume? does the arrow need to point toward the engine or the booster? Is it also called a non-return valve?

[nrubenstein]

I had the iX booster, it is the one that failed. Where does the check valve go, between the booster and the engine I assume? does the arrow need to point toward the engine or the booster? Is it also called a non-return valve?

Yes. It gets installed anywhere between the booster and the intake manifold, depending on which one you get.

[fronton]

If it is part number 10 or 17, I have one installed already: http://bmwfans.info/parts/catalog/E3...it_depression/

[dogsbark26]

Wait a minute. I'd check that your booster is getting vacuum from the engine before replacing it. Those iX boosters are too expensive to replace without checking.

Mr.Swiss was talking about a E32/ix booster - not the e30 iX booster you have though.

[fronton]

Wait a minute. I'd check that your booster is getting vacuum from the engine before replacing it. Those iX boosters are too expensive to replace without checking.

Mr.Swiss was talking about a E32/ix booster - not the e30 iX booster you have though.

I pulled the hose off the booster with the engine on and had strong suction so it must be the booster. There is only one iX booster, what e32/iX booster are you talking about?

I assume he meant a e32 mc connected to a e30 ix booster. I won't do another ix booster because the location of the plug is on the strut tower side which makes it impossible to get a strong connection with the M3 tower being in the way.

[dogsbark26]

My bad. You are clearly correct.

[fronton]

I robbed a check valve from an eta in the sally. I suggest you do the same when you replace your booster.


Hey! Why not take the chance to try an A4 1.8T or an E32/ix booster?

I love the ix booster and e32 master feel. Not as grabby/touchy, but doesn't need much force to engage ABS.

Looks like A4 boosters are dirt cheap. How do I hook up the backside to the firewall and the push rod to the pedal though?