1997 Riviera brake booster

[rgaines]

I have a leaking master cylinder which I was told has likely ruined my brake booster. (everything is working fine now, but needs to be fixed.) I got a new booster and master cylinder, but one of the bolts on the booster is behind the lower steering column boot and in not accessible. Any advice on how to get that nut off?

 

[2007LucerneCXL]

Not sure on which nut, but here's a couple of diagrams that might help. The only option I see from the diagrams is that the steering colum may have to be dropped, hopefully someone else on the forum may know more information about this.

 

[rgaines]

Not sure on which nut, but here's a couple of diagrams that might help. The only option I see from the diagrams is that the steering colum may have to be dropped, hopefully someone else on the forum may know more information about this.
View attachment 28569 View attachment 28570

thanks for the reply. The lower bolt nearest the driver side door is completely blocked by #11 on the 2nd diagram. I can get a deep socket partly on the nut, but it's at too much of an angle to do any good.

 

[rgaines]

thanks for the reply. The lower bolt nearest the driver side door is completely blocked by #11 on the 2nd diagram. I can get a deep socket partly on the nut, but it's at too much of an angle to do any good.

I'm going to try to find a 1/4" drive 15mm that's not as long as the 3/8" drive one I was using. Maybe the smaller shank will give me enough space.

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[2007LucerneCXL]

Unfortunately the Chilton manual basically says to remove the 4 nuts and no additional instructions so it may be in the type of tool being used, hopefully that is it.

 

[MelsRegal]

Not really sure you have to replace the booster.
Did you research that or just assumed it was necessary?
Did you check if there is a seal on the booster that would make fluid entry minimal if at all?

 

[rgaines]

Not really sure you have to replace the booster.
Did you research that or just assumed it was necessary?
Did you check if there is a seal on the booster that would make fluid entry minimal if at all?

I should probably look at it more closely. I was told that since the master is leaking on the back side onto the booster, the brake fluid is able to get in the booster and will degrade the diaphragm and cause it to fail.

 

[LARRY70GS]

I should probably look at it more closely. I was told that since the master is leaking on the back side onto the booster, the brake fluid is able to get in the booster and will degrade the diaphragm and cause it to fail.

I would not assume that. If the booster is working, leave it alone. I never try to fix something that isn't broken.

Having said that, you may be able to drop the steering column. Can you get to those bolts to drop the column from underneath, it's been a while since I have looked on my 98. If you have to remove the lower knee bolster, the instrument panel fascia needs to come off. I have a word document on how to do that.

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[Regal LTD Coupe]

I agree; I wouldn't replace the booster unless I knew it indeed had kicked the bucket but it's good to have new parts on the shelf for the future anyways. I would just replace the master cylinder for now and hope the rest never needs to be done. That said, others have said they believe the boosters to actually need replacing at some point but at least in my car's case it still seems to work fine after 28 years and 149k miles, assuming it's the factory booster.

Regarding the inaccessible fastener; if you were to heat up and bend a wrench in an appropriate fashion, do you think that might be able to unfasten it? I have never done it but it's a common thing for some mechanics to do in order to get into difficult to reach areas.

 

[HotZ28]

I have replaced many master cylinders that were leaking through the piston rod. The fluid leaks down between the MC and the booster, not into the booster! You have got some bad advice to replace that booster! In addition, it is very common, if you go to a Quick Lube station for an oil change, the Neanderthals they have working there will check all fluids as directed. Usually, when they twist off the master cylinder cap, they break the seal between the reservoir & the master cylinder that will start leaks. Seen that many times!

 

[2007LucerneCXL]

Considering that no one has actually seen your vehicle or knows anymore about the condition then what's been posted its impossible to know for sure. Unless it's a budget issue, most boosters are in that $100.00 mark, and you have already have purchased a new booster along with the old unit somewhat removed go ahead and continue as it won't hurt. My experience is "if in doubt, pitch it out", if it can't be confirmed good.

As no one posted how to check a brake booster here's a site that offers a couple of methods, there's more online if needed.

How to Test a Power Brake Booster | YourMechanic Advice

If your brakes start to feel spongy, the root cause may be the power brake booster. Test your power brake booster to see if it needs replacement.

www.yourmechanic.com