The local shop is "thinking" my master cylinder needs to be replaced, but suggested the lines may have air or moisture in them and I could try to have them bleed the lines- otherwise replace the master cylinder.

Their is a lot of pedal travel- down to 2" from the floor- but then firm and stops well. I can pump them up a tiny bit, but not much. The brakes are firm once 2" from the floor.

Should I spend $90 to have them bleed the lines see if that fixes, or should I replace the master cylinder?

THANKS!

1994 940 Turbo- 302k miles

 

"2" from the floor" doesn't mean much... I'd bleed them... why not try to do it yourself? Easy DIY job...

 

If you apply firm and constant pedal pressure for a minute or two and the pedal slowly sinks, you need a new master cylinder.
If the pedal drops then stops firm, and will stop the car well at that point, you need to bleed.
*edit* If your local shop couldn't figure out to use this old and reliable technique, you need to find another shop.........

Regards, Andrew.

 

Thanks! I think their point is, it's a little inconsistent- it returns a little bit. Their a local shop I thought I'd try out. Thanks VERY much for your advice.

Regarding DIY bleed- It's winter in MN, unheated garage, and I have a tendency to cause more problems I also need to buy a good repair manual.

THANKS!!

 

I'd have to completely agree with Andrew on this. I would think most shops could pinpoint this issue. Hydrolic breaks arnt exactly new technology =)

I'd bleed them first.
If you were to do it yourself one of these fancy vacuum bleeders may help out so you dont have to clown around with someone pumping the breaks for you. Speed it up too so you can get out of the cold.

 

If you have them replace the master cylinder they will have to bleed the brakes at that point anyway. The one on my 81 240 was about $30 for the part and I did it the old fashioned way bleeding them out with a helper pumping the brakes. Just as a side note one of my older GM cars was doing the same thing and it was the master cylinder causing it.