Brake booster vacuum line?

[thecheat]

Is this a regular vacuum hose? It looks like it would be 3/8 ID - is this right? From what I can see of my existing line it's starting to deteriorate.

I have a lot of pedal travel and it takes more pressure than I'm comfortable with to stop vs any other car I've been in. Would this be a symptom of a leak in this line? I'm positive I have a vacuum leak but haven't been able to narrow it down even after replacing most of the hoses.

I've been trying to buy a vacuum gauge but I'll be damned if I can find one locally anywhere. I can find boost gauges and cylinder pressure gauges but nobody sells a vacuum gauge.

[phils94850]

Usually if you have a lot of pedal travel then it could be due to a bad master cyl, which isnt very common, pads are getting worn, or your brake rotors are getting thin, or you have air in the system. I would check your pads and if they look good then i would try bleeding the system. A large vac leak like a brake booster line would cause the engine to run very poorly and you would possibly have a hard pedal. It would feel like when you push on the pedal several times with the engine not running.

You can install a boost gauge that shows vacuum also to solve the problem

[thecheat]

Well the front pads are brand new, fluid has been flushed a few months ago, and the rotors are fairly new.

So it is possible that the hose (while ugly) is OK for now. I thought about getting a vac/boost gauge but it won't be particularly accurate.

[VolvoTurbo850]

Sounds like you got the mechanical parts of the brake working. But as phil suggested you need to consider the part which activates the braking system too.

Even if you replaced the parts was it bled properly?

Is your car operating properly? A big leak like that off the throttle body will sure to cause other issues. If you check under the air cleaner there is actually a plastic connector. This means you do not have to replace the whole hose just about 3 feet of it.

So if it is chewed up why not replace it and see the change in the operation of the vehicle and brakes. It wont cost you much and a little time.

[jblackburn]

If in doubt, change it. My brake feel improved nicely after changing that hose.

I believe it was 3/8 - it's something metric, but that worked.

[thecheat]

So, yeah...April, October.... I just got around to doing this. Well it would seem that it did something as my brakes seem to grab more and I have quite a bit more torque according to the butt dyno. Now flooring it gives modest power and then it's "prepare for takeoff" around 3000 rpm and the car starts torque steering with the boost gauge almost all the way to the right!

This was so easy I regret not doing it earlier... Bought 4 feet of 9mm or 3/8" I'd vac line and replaced the two sections in half an hour. I believe the booster side was bad as the intake side looked to be in better shape. However, I had to cut the intake side in half as it was no longer flexible enough to easily remove.

No idea what the MPG gains are, if any. I'll be driving in to work on Wednesday and that'll be a lot of highway driving. Right now I've been thrashing it around town and have 14 mpg to show for it... which isn't too bad for only maybe 20 miles of a very heavy right foot.

The brakes still, in a word, suck. They are a million times better now, though. Before it seemed like no matter how hard I pushed, the hydraulic system would only give out a certain amount of pressure. Now the braking force engages in a more "positive" way.

[Minkheel]

I think I need to replace the brake booster vac lines on my 1999 V70 GLT. Any “how to” videos or DYI instructions out there?

[abscate]

Be careful with the fitting INC the brake booster. It’s plastic and very expensive, and I’m not even sure its available new any more, you may need to buy the whole booster