Brake lines, vacuum hoses and flushing the system

[brucepelletier]

I've done a search on the site but haven't found a post that covers all three of these topics together, so here goes.

My 90 Q is going in for a front and rear brake job this Saturday. The rear rotors will also be replaced.

The car has 113,00 miles. Should I have the rubber brake lines replaced at this time? I believe they're original.

Also, I've found mention of brake vacuum hose(es). I'm guessing this has something to do with the power brakes? If so, what is the replacement scheudule for these?

Lastly, I plan to have the brake system completely flushed again. Does this involve the ABS unit and if so what should I be aware of when talking to the service writer and the tech. I want to be sure its done correctly. I plan on using Valvoline Syntech again.

Thanks for all responses. This site is the best.

[911/Q45]

Good questions! The brake lines are definite candidates for replacements. Many of us use stainless braided lines that cost about $40 and firm up the pedal feel slightly, or the factory lines are fine. The power brake vacuum hoses should be replaced when all the other underhood rubber is done, certainly by 13 years and 108K. There are two bleeders on the ABS unit that should be flushed first until the fluid is clear before the tech moves on to the calipers. They are easily seen on top of the unit.

[Q451990]

There are two bleeders on the ABS unit that should be flushed first until the fluid is clear before the tech moves on to the calipers. They are easily seen on top of the unit.

Flush order is LR, RR, LF, RF, Front ABS, Rear ABS at least in the service manual.

Heath

[911/Q45]

Hmmmm? I would justify my order by getting clean fluid in the master cylinder and ABS before taking the long trip down to the calipers. I wonder why the order in the manual?

[DAEDALUS]

Longest distance to shortest distance...I'm guessing to reduce the chance of getting a bubble lodged in the lines somewhere.

[fxjackso]

I think we are talking about two different things. The service manual order is to bleed. I would agree that in flushing if you can get the old fluid out of the master (with a clean baster) and then the ABS you will be seeing clean fluid at the calipers a lot sooner. After the flush, back to the book to bleed.

[911/Q45]

If you bleed until it's clear, didn't you just do a flush? My last semantics game input!