[Pawtang]

Hey,

So I've got the old "oil in the brake booster" problem - and all the built up oil is being sucked into the intake manifold when its at low pressure and burning off once the engines hot enough, dumping giant clouds of blue. I started by replacing the nipple for the connection to the intake manifold as the old one was severely degraded, so at least I won't have my vacuum line leaking through there. Now, I know I've likely got either a bad brake booster vacuum pump, or at least a leak there. I also have a ****ty valve cover gasket that needs replacing, which I think might also contribute to the leaky vac, but I'm not sure if that would be a factor (first timer).

Question is, presuming I get all the oil out of the brake booster and bleed the brakes and the booster turns out to be okay even after sitting with oil on the diaphragm for a while (fingers crossed) - or, I replace the brake booster - I still need to find the source of the oil and fix that. I've seen that the updated vacuum line has a check valve that stops flow from the vacuum toward the T-joint. This would obviously stop oil from entering my brake booster, but then where would that oil go otherwise? Will I have issues from a buildup of oil at the vacuum pump or will it just kind of slowly leak out around there and not be an issue?

Also, how difficult is it to replace the o-rings and gaskets on the vacuum pump and its connection to the cam shaft? Could this potentially solve my problem?

 

[jakejm79]

Its when the manifold vacuum is greater than the vacuum the pump makes that the oil will get drawn up to the T and into the brake booster. With the 2nd check valve in place there will never be a time when this happens so its not like the oil would be sucked up to the check valve and stay there, the check valve eliminates the possibility of that happening.

Do you have the PCV #6 update, if you have multiple leaking seals and/or gaskets maybe your crank case pressure is higher than it should be?

 

[Pawtang]

Its when the manifold vacuum is greater than the vacuum the pump makes that the oil will get drawn up to the T and into the brake booster. With the 2nd check valve in place there will never be a time when this happens so its not like the oil would be sucked up to the check valve and stay there, the check valve eliminates the possibility of that happening.

Do you have the PCV #6 update, if you have multiple leaking seals and/or gaskets maybe your crank case pressure is higher than it should be?

Haven't updated PCV yet. I wan't to make sure I can solve this oil burning problem before I put more money into this car. That is next on the list though.

If I'm understanding you correctly, are you saying that oil only even gets pulled into the vac pump from the crankshaft in the first place because of the manifold vacuum? So having the second check there will eliminate oil flow into the vac pump -> hose -> booster? And simply adding a check valve that stops this flow is a good solution?

 

[jakejm79]

Not quiet, the seals in the pump can start to leak, leading oil to get in the pump which then gets sucked up the hose via the manifold vacuum, if that manifold vacuum isn't present (due to the 2nd check valve) then oil remains in the pump (or leaks externally or back to wherever it came from) its not like the pump will become completely overcome with oil that the level will rise so that it overcomes gravity and just rises up the hose.

The seals in the pump leak, just because of age and the fact that a horizontally mounted pump isn't ideal (much the same way the distributors leak in the NA models), normally this wouldn't be a huge issue, you'd get a minimal amount of oil remaining in the pump and it would eventually drain out or leak out or get sucked away with the vacuum the pump generated.

Problem is when you have a vacuum on the hose, sucking away from the pump that is stronger than the vacuum the pump is putting out, the oil that has now collected in the pump is now drawn up the hose and to the booster. The 2nd check valve makes sure there is never any vacuum away from the pump, therefore the oil can't be drawn away from it.

In theory the 2nd check valve shouldn't be needed, the pump always generates vacuum and is there to supplement the manifold vacuum, if the manifold vacuum is greater then at that point the pump isn't needed so it doesn't matter if its over powered by the manifold vacuum, problem arises when the seals leak and oil gets sucked up, something that wasn't accounted for with the single check valve design.

 

[Pawtang]

Do you think I'd be able to replace the 2000 brake booster with a used booster from a later 9-3 model? A lot of the ones I'm finding on ebay for a reasonable price are from 03 and on models. I can't imagine much has changed in terms of fit or function... And I'd wager the diaphragm is shot from the oil built up in there. I was going to try to pump it out, but that's probably not sufficient, although I'm hoping it will at least solve the oil burn (combined with the new vacuum lines w/ check valve I ordered) until I can replace the booster and have power brakes going again...

Also, how would I know if its brake fluid versus oil in there? Just a quick check of my brake fluid level? If its brake fluid, I would need to replace master cylinder as well, correct?

 

[jakejm79]

Nope, 03 and up (04 if its a convertible) is a completely different car, about the only parts that readily swap would be the wheels.

On top of that in the og9-3 (1999-2002) changed the MC and booster from 2001 on wards, the bolt holes/studs that hold the 2 together are in different places, so you will need a booster from any ng900 or og9-3 up to and including 2000. I'd find one from a MT or 1999 and earlier car since you know there will be no oil in it (they didn't have cam driven vacuum pumps).

Unlikely to brake fluid, that would be a very uncommon failure, plus if you were losing enough for it to be burning the reservoir would empty pretty quickly, plus you'd notice it with the pedal feel if the seals in the MC had failed that badly.

 

[Pawtang]

Awesome, I found one from a late 90's 900 on ebay for just under 100. Thanks for all your help by the way, you've practically guided me through this whole thing. I'll see how this replacement goes...

 

[Pawtang]

Well, I managed to pull about a quart of engine oil out of my booster with an oil suction gun. Was surprised there was that much in there.

Turns out the new vacuum hose I ordered, the one with the second check valve, has a different configuration, as it was made for the 95. Unable to fit it into my car as the hoses are rigid. Do you think it would be worth trying to cut out a check valve from the hose I ordered and superglue it into the old hose? Or is that just nuts? I feel like I should be able to splice any old check valve in there, but I'm worried about messing with the rigid hose.

 

[jakejm79]

I wouldn't cut up the new line, I'd return it for the correct one. You could splice in a check valve into the old line (I've seen people use rubber hose that slips over the hard line and some clamps) until you can get the correct line.

 

[Pawtang]

I wouldn't cut up the new line, I'd return it for the correct one. You could splice in a check valve into the old line (I've seen people use rubber hose that slips over the hard line and some clamps) until you can get the correct line.

Yeah I'll probably just return it. But what sucks is the same line with a second check valve in it is, for some reason, 80 dollars instead of 20/30.

How plausible do you think it is to buy one of these http://www.mcmaster.com/#air-check-valves/=13modip
Simply cut the old line, and then superglue this valve in? I don't see where there could really be any functional difference. Especially if I do superglue on the outside and maybe some silicone on the outside for extra support. I don't know, I just don't wanna drop 80 dollars for a simple vacuum hose.

 

[jakejm79]

Do you not have a you pull yard near you, should be able find one there for cheap, just test the check valves before you buy it.

I guess you could glue in any generic check valve, just make sure you put it in the correct way.

 

[Lissy]

Hey,

So I've got the old "oil in the brake booster" problem - and all the built up oil is being sucked into the intake manifold when its at low pressure and burning off once the engines hot enough, dumping giant clouds of blue. I started by replacing the nipple for the connection to the intake manifold as the old one was severely degraded, so at least I won't have my vacuum line leaking through there. Now, I know I've likely got either a bad brake booster vacuum pump, or at least a leak there. I also have a ****ty valve cover gasket that needs replacing, which I think might also contribute to the leaky vac, but I'm not sure if that would be a factor (first timer).

Question is, presuming I get all the oil out of the brake booster and bleed the brakes and the booster turns out to be okay even after sitting with oil on the diaphragm for a while (fingers crossed) - or, I replace the brake booster - I still need to find the source of the oil and fix that. I've seen that the updated vacuum line has a check valve that stops flow from the vacuum toward the T-joint. This would obviously stop oil from entering my brake booster, but then where would that oil go otherwise? Will I have issues from a buildup of oil at the vacuum pump or will it just kind of slowly leak out around there and not be an issue?

Also, how difficult is it to replace the o-rings and gaskets on the vacuum pump and its connection to the cam shaft? Could this potentially solve my problem?

How do you replace the nipple/bushing?

 

[jvanabra]

What part do you need? IME, it's the red ring that typically fails, and replacing it alone is sufficient. Press the red ring down, withdraw the plug, then gently pry the red ring out. Going this route you'll have the actual fitting left over.

 

[Lissy]

What part do you need? IME, it's the red ring that typically fails, and replacing it alone is sufficient. Press the red ring down, withdraw the plug, then gently pry the red ring out. Going this route you'll have the actual fitting left over.

can i replace the whole thing?

 

[jvanabra]

Which specific location are you referring to? The one in the intake manifold, or the one in the intake pipe, or the one in the vacuum pump?

 

[RovingSaab]

I had some trouble with a couple of these. In my case, replacing the o-rings solved the problem.

Sent from my SM-G930P using Tapatalk

 

[Lissy]

Which specific location are you referring to? The one in the intake manifold, or the one in the intake pipe, or the one in the vacuum pump?

There are 2 that attach to the new line

Which specific location are you referring to? The one in the intake manifold, or the one in the intake pipe, or the one in the vacuum pump?

Which specific location are you referring to? The one in the intake manifold, or the one in the intake pipe, or the one in the vacuum pump?

Intake manifold and intake pipe i believe. I know i can take out the red parts but is it hard to replace the whole bushing on both of those?

 

[jvanabra]

The manifold isn't that difficult, but I'm not sure the one on the intake pipe can be replaced. I've personally not tried, but I think there's a risk of damaging the pipe.

 

[Lissy]

The manifold isn't that difficult, but I'm not sure the one on the intake pipe can be replaced. I've personally not tried, but I think there's a risk of damaging the pipe.

who do i get it out since there are barbs

 

[BobSaabit]

I've tried to remove them from the charge pipes several times and never had any luck. I've broken the whole fitting on the pipe each time. I would just replace the red ring and the o-ring that's inside the nipple. That's what leaks.

But, I have one downstairs still stuck in the little support arm thingy. I'll give it another shot later today and see if I can get it to release somehow.