CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Vacuum brake accumulator -- do I have to fix?

there’s a noise that sounds like a seagull coming from under the hood near the steering wheel. Turns out it’s the vaccuum brake accumulator & there was a recall on this. Unfortunately I had the part replaced back in 02, so Montero won’t fix it a second time. I only use the vehicle on the weekends & didn’t see any reduction in the brake performance so I put the repair off since it was over $1000. That was over a year ago. How important is it to fix this? Other than the really odd noise there doesn’t seem to be an issue… I’m just trying to decide the future of my truck since the transfer case is gone & I can’t use 4wd or AWD andmore. That’s been broken & flashing about a year too… On top of that the AC is broken & now there’s a light tapping noise whenever the car is in gear, but not in park… I really love my truck but am losing hope. Everyone says it’s not worth fixing. 140,000 miles. Love driving it, runs great in my opinion…

The decision of whether to repair this should rest largely on the strength of your legs.
When that vacuum accumulator finally fails, it is going to take an incredible amount of lower-body strength to stop the car if it is traveling at anything more than walking speed. If you are prepared to accept the liabilities involved in possibly not being able to stop the vehicle, then you can skip this repair.

However, given the condition of the rest of the vehicle, I really think that you should already be shopping for a replacement vehicle anyway.

There is always a number of dollars, at some point your availible dollars are not worth the benefit. Sell it or scrap it for charity. Please tell the buyer all the issues and adjust the price to match. The charity benefit can be more than the actual sale value. You can write off the value for a charity donation for a tax break.

At least disconnect and plug the vacuum hose feeding the brake booster to stop the noise and the large vacuum leak which will upset the vehicles computer by allowing all that un-metered air into the engine…NOW it’s going to take some leg effort to stop…How old is this POS and how many miles on it?

@Caddyman & others. I agree that safety is an overriding factor when deciding what to do with a car. In OP’s case, I would sell it for parts, or donate it and get a tax receipt.Driving with dangerous brakes is criminal and irresponsible.

We dispose of a vehicle when 1) it costs too much to fix to keep it going reliably, 2) It is unsafe and can’t be made safe, or 3) it has rusted so badly as to be unsightly. Having said that, we kept a 1977 Dodge Colt going for 20 years, a 1984 Impala for 20 years, a 1988 Caprice for 19 years and a 1994 Nissan for 18 years.

Thank you everyone for your input! You’re right, it is irresponsible to not address the brake issue. I’m going to try disconnecting the vacuum hose as Caddyman suggested & make sure I can safely & predictably stop the vehicle. It’s got 140,000 miles on it & if I think of it as a no-frills truck w/out AC or 4wd then there’s really not any other issues w/ the truck. 2 wd works fine… The tapping noise turned out to be just a bracket on my exhaust that needed to be fixed – the vibration when it was in gear as opposed to park was rattling it…

“I’m going to try disconnecting the vacuum hose & make sure I can safely & predictably stop the vehicle.”

Vehicles with disc brakes require a HUGE amount of strength to stop the vehicle if it is traveling at anything faster than walking speed. So…you might want to verify how much liability insurance coverage you have if you plan to conduct this test on a roadway.

If the booster’s diaphram spring is removed braking effort will be greatly reduced and it might be safe to drive as a farm vehicle.

ok, so much for that idea… I’m desperate to keep this truck running. Any thoughts on the repair itself? My father is a retired mechanic but not computer savvy. Like the rest of you he thinks it’s time for a new car. I just can’t see finding anything similar for under $3,000 & would rather put it into repair if I had to… Is this a part I could get from a junkyard?

I’d check with the local junkyard and with the retail chain auto parts places to get an idea of what a replacement part would cost. It might not be that much. There’s an off chance a specialialty brake shop could fix it even. There’s undoubtably some rubber part that has sprung a leak is all. No harm asking anyway.

A charitable deduction is never worth more that the actual sale price. If you can’t itemize you get no benefit at all and even if you can, you can only deduct what the charity gets for it. It is also only a deduction, not a credit. For example, if you get a $1000 deduction, it doesn’t deduct $1000 from your tax bill, only from the income you pay tax on. If you are in the 15% bracket, that would be worth at most $150.

If the model year was mentioned I missed it. Here is the part for a 2000 Montero.

It can be installed in less than an hour by anyone with average abilities and basic tools.

Another place to check is rockauto.com.

What year?

awesome! thanks. the one for my vehicle (2001 Montero, not a sport) is a bit more, but if the installation is still pretty straightforward that would be fantastic. I assumed since it was tied to the engine somehow & involved vacuum pressure it required some sort of special tool / expertise… http://www.autozone.com/autozone/parts/Brake-Power-Booster/_/N-8kn7z

Rock Auto & Autozone specifically state the part is sold w/out master cylinder – does that need to be replaced w/ the power booster?

Nope, completely separate. While it’s a pretty simple swap, you’ll want someone familliar with brakes to do it.

Fantastic! thanks so much! I was so close to either giving up or turning over the credit card to the dealer. Amazing they stay in business w/ such a markup.

You seem so devoted to this rig that maybe the best thing for your soul is to commit to fixing ALL the problems (even if they don’t make financial sense). But first, a few questions:

  1. How is the body, paint, interior, and glass? If it’s pretty good, or better, go to #2. If it’s a rust bucket (check underneath for weakened frame), or really hammered, part it out and scrap what’s left. If it’s pristine, straight, and paint still shines when waxed, fix everything and be happy.
  2. What’s the oil consumption? 1 quart per 1000 miles or even better, go to #3. If less than 500 miles per quart, part it out and scrap what’s left unless you can do an engine swap yourself.
  3. Is it an automatic transmission? If yes, go to #4. If it’s a manual, get the fluid changed, then fix everything and be happy.
  4. Has the automatic transmission been serviced regularly, ie: fluid change and filter, every 30,000 miles? If yes and you like a little uncertainty in your life, fix everything and be happy.
    (and keep up with the transmission fluid changes). If no, go to 5.
  5. Has the transmission ever been rebuilt or replaced? If yes, fix everything and be happy. If no, find out what an independent local transmission shop would charge when you do need a complete rebuild. Add that to the cost of the other repairs, and then start checking Craigslist to see how much it would cost to buy a similar vehicle with all this stuff in good condition., and then make your choice.

BTW, there’s no real need to rely on the dealer for repairs, and often a good case to go elsewhere. Look for a trustworthy independent local shop and see if you get good service for lower prices. That may save you enough money to warrant keeping this sweetheart on the road.

Good luck!

The decision of whether to repair this should rest largely on the strength of your legs.
When that vacuum accumulator finally fails, it is going to take an incredible amount of lower-body strength to stop the car if it is traveling at anything more than walking speed.

And don’t forget that next week your wife may be driving your car when it fails. Will she have the strength to stop safely?

I’m just trying to figure out how a 4WD vehicle that only drives 2 wheels now with a broken AC and failed brakes qualifies for “runs great”