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Accidentally drilled a hole through my brake booster.. [NEED ADVICE]

This is my first time on this website so I do not know if I am doing this right. It is going to be a very long topic but PLEASE take your time to read it and give me some advice on what to do.


I got subwoofers yesterday and I went to my friend for help. So of course we needed to get the hotwire from my amp to my battery. So we tried looking for a boot, but we could not find any. He had an idea to drill through my firewall. While he did that I went and popped my hood. We had a light shining from where he was drilling so I could see if there was any holes being made from under my hood. He drilled and he drilled but I could not see any light. We failed getting the hotwire to my battery. blah blah blah [fastfoward] > I started my car and then I started hearing a hissing noise in the cabin. The noise was directly in front of me down by my foot area, it was behind the brakes. I got completely scared. Then the “check brakes” came on… blah blah blah [fastfoward] > His dad came home (keep in mind that his dad is an actual mechanic and he has ALOT of knowledge about cars. He does not work at a mechanic shop, he just volunteers to help at an autoshop for college, he built an engine at 9 years old with HIS dad. So lets just say he is way above average in car knowlege). I told his dad everything that happened and His face was priceless. He popped the hood and He knew exactly what happened. He said that my friend drilled through the brake booster, and thats why the hissing noise was present. The hissing noise would stop when I applied the brakes “kinda” harder. Then when I depressed it the hissing noise came. His dad got silicone adhesive and tried squirting as much adhesive he could through the tiny hole in the firewall so it could reach the brake booster. We both knew it was DOUBTFUL that it would stop the hissing. We took it for a test drive to see if the brakes would still work. The drive was actually good, the brakes were normal. Everytime the car accelerates the hissing would stop and AGAIN everytime the car would brake, the hissing would stop. That night the check brakes system light was on. The next day the check engine light came on, so I called him and he said that it would come on because of the air/vacuum leak.

Since it was his sons fault. (it was an accident, crap happens) His dad said for me to not worry about it and that he would fix it. (that would be in a week or two because he has a project he is currently working on). I am currently still driving it. Breaks are normal. Just the hissing noise is present and the check engine light and check brakes system is on. I even went on the highway and went 60-65 and did a hard stop. I know that might sound stupid but the brakes were still normal. Now the size of this hole that my friend drilled through is probably the width of a toothpick, or maybe even a toothpick and a half. So that hole is really small. maybe that is why I am not losing alot of break power. With the given information of the size of the hole, would it be POSSIBLE for my friends dad to just take the brake booster out and just PATCH the hole? I mean it IS a very small hole. I am just glad that my friends dad is able to do all this labor for free, even if I have to go to the junkyard or online to get me a new brake booster, but i really do not want to spend all that money on a new brake booster.

I would use a short sheet metal screw with a little epoxy under the head.


Send us a picture of the damage. I think oldtimer_11 has a pretty good and inexpensive fix here.

Old-timer 11 has a pretty good idea, but I personally like to play the safest route especially when it comes to brakes. The booster is coming out anyways, so cut your losses and replace it. Mistakes can be very expensive, but this one isn’t by doing a complete repair.

Sure its doable… A tack weld would be ideal however.

Thank you guys so much for advice. I will for sure show his dad what old timer said… I wouldn’t be able to show a picture of the damage right now because it was drilled through the firewall. The dad isn’t going to be able to do work on this for another week enough cause he has holiday plans with his fam… in the meanwhile do you think it’s okay for me to drive with this?

Good thing is, I already searched up a replacement part for me and it will only cost me $80 plus $15 for shipping. Atleast I just just get to spend $100 and NOT the extra $500 for labor by going to a mechanic shop because the dad is able to do this for free. But I’m just going to wait how it all turns out when he comes back before I buy anything. Cause patching it might just work.

When you decide to tackle the subwoofer again, remember to put a fuse within 18 inches of the battery. Otherwise you might set your car on fire.

Thank you for the tip, as I have no knowledge for this haha… i ended up going to a audio shop and they told me to drill underneath my car where I would sit. Approximately under my knees there was a sweet spot of metal underneath the carpet. I ended up drilling a hole there and so I just dropped the wire from the hood then underneath the car to the hole I drilled. Then boom there wire is inside my car so I just led it to my trunk and connected it to my amp. I had my friends dad help me so he knew where to drop the wire at from the hood and also he made sure the wire didn’t interfere with anything too hot, moving, spinning, and especially the suspension.

Aside from that the fuse is about 10inches to 12inches from my battery. Now all the work I need to do is connect my remote wire to my stereo and then using my lineout converter to my factory radio. I might end up just using the speaker wires in my built in subwoofer/speaker that’s right in my trunk.

If you hear air hissing at the brake booster, he drilled a hole thru the diaphragm inside the brake booster.

The brake booster needs to be replaced.


Would it be possible if he just drilled though the metal part of the booster and not the diaphragm.


If you hear air hissing, the diaphragm has a hole in it.


i did replace the diaphragm on my 76 impala. separating the 2 piece steel shell was not hard. yes i junkyard unit probably would have been easier.

[HELP PLEASE] So I have decided to just buy a new brake booster replacement part. Problem is There is only like two existing used brake boosters on ebay. I am afraid someone will buy them before I get to it. Would there be any other cars that I can find online with the same brake booster I can use for my 2008 Acura RDX?

Why does it have to be online. Any parts house will have one or at least get it overnight and with a core charge you can just drop off the old one at your convenience . What if it does not fit then you have shipping all over again.

No way am I putting a used brake booster on my vehicle.

1 Like

I would agree to simply buy a new unit… instead of trying to fix yours (not really feasible if diaphragm has a hole) or buying a used unit. You want to do this one time…so buy a new one. Rock Auto has it for $113… get it and be done with this the right way.

You have to send your brake booster in to have it rebuilt.,2008,rdx,2.3l+l4+turbocharged,1440494,brake+&+wheel+hub,power+brake+booster,1884

There’s absolutely nothing wrong installing a used brake booster. I’ve done it many times.

As long as nobody has drilled a hole in it.


Why is it costing you anything? You didn’t drill a hole in your brake booster.

Trust me, I have called all over the place. This car (2008 Acura RDX) is not common around here.

I know I didn’t drill the hole, but I do not want to put my friend through that. I was the one that went to him, and it was a freak accident. I could have told him to stop if I wanted before he started drilling, but I didn’t. Anyways, its better for me to spend $100 and having is dad replace it for free instead of going to the mechanic and having to be charged labor fee of $500+.

I have found more and more brake boosters for my car. I found one that is $70 on ebay. I might go for that one.
Thanks mates.