SC brake fluid reservoir tubing

deeking55 · 03-01-2011, 12:58 PM

I have a tube on the very top of my brake fluid reservoir that looks as it functions for overflow. However, the terminus of the tubing has sheared off and I can't tell where it was supposed to end or how important the function of that tubing is. Should I pull it completely or where should I run the new line too?
cheers-

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by deeking55

I have a tube on the very top of my brake fluid reservoir that looks as it functions for overflow. However, the terminus of the tubing has sheared off and I can't tell where it was supposed to end or how important the function of that tubing is. Should I pull it completely or where should I run the new line too?
cheers-

It dumps under the car, it's important to the extent that fluid level in the reservoir rises and falls w/ usage and temperature, you don't want excess fluid to dump into the trunk. Similarly there should be a line from the battery that dumps under the car.

For most street use and if the res. level isn't topped off there won't be any excess. Nevertheless it's best to replace that line

Wilhelm · 03-01-2011, 01:42 PM

Quote:

Originally Posted by deeking55

I have a tube on the very top of my brake fluid reservoir that looks as it functions for overflow. However, the terminus of the tubing has sheared off and I can't tell where it was supposed to end or how important the function of that tubing is. Should I pull it completely or where should I run the new line too?
cheers-

I assume you know...make sure you dont get any brake fluid on your paint !

Howard M · 03-01-2011, 01:43 PM

If you drive the car agressively (autocross for instance) brake fluid will slosh into the overflow pipe (or elsewhere if it's not there) even if the MS is not overfilled.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by Howard M

If you drive the car agressively (autocross for instance) brake fluid will slosh into the overflow pipe (or elsewhere if it's not there) even if the MS is not overfilled.

It may, not necessarily will

deeking55 · 03-01-2011, 02:56 PM

Great. Where should the line run in order to dump the fluid? As convoluted as the tubing runs, it seems as though it would take a fair amount of pressure to run brake fluid all the way to the end. And yes, NO to the paint!

porschenut · 03-01-2011, 03:27 PM

here's a picture of where the tube exits the trunk. It travels along the top of the left fender and then exits forward of where the battery is. This car is an 86 Carrera, btw.

Wil Ferch · 03-01-2011, 03:28 PM

It would also "Spill" simply by pushing back brake caliper "pucks" while putting in new brakes. You tend to wear brake pads down slowly, and you "occasionally" refill the reservoir. At some point, the reservoir may be "full" and the old brake pads are "worn"...and you proceed to change out pads and put "fat" new pads in....that's when the overflow will then spill into the car without a vent line.

The vent line runs along the front/driver fender seam near the trunk lid cut-line....and finds its way to the front of the car near the battery and disappears to a very small opening to the outside. Truth be told...if I didn't have an original line to follow, it would be very difficult to trace.

Flieger · Flieger's Garage

Wonderful that Porsche was still dumping brake fluid on the ground in 1986.

SCOTITUDE · 03-01-2011, 07:54 PM

I have a small bottle mounted next to the brake booster and have the end of the overflow line run through a hole drilled in the cap. Its a track car so there is constantly fluid coming out of the hose from heavy cornering. Even for street use I used to get brake fluid all over the bottom of the car when the tube ended underneath. The underside of the car was full of it. A poland spring bottle served this purpose very well for a bunch of years.

schumicat · 03-02-2011, 03:56 AM

that is why you should remove some fluid from the reservoir with a dedicated turkey baster before you push the piston back to fit new pads. On my car the PO capped the nipple for the "overflow" line. Anyone have a photo of exactly where the line connects to the fender? The photo above shows where the line runs, but not where it connects to the m/c. Thanks

Quote:

Originally Posted by Wil Ferch

It would also "Spill" simply by pushing back brake caliper "pucks" while putting in new brakes. You tend to wear brake pads down slowly, and you "occasionally" refill the reservoir. At some point, the reservoir may be "full" and the old brake pads are "worn"...and you proceed to change out pads and put "fat" new pads in....that's when the overflow will then spill into the car without a vent line.

The vent line runs along the front/driver fender seam near the trunk lid cut-line....and finds its way to the front of the car near the battery and disappears to a very small opening to the outside. Truth be told...if I didn't have an original line to follow, it would be very difficult to trace.

Kemo · 03-02-2011, 06:50 AM

I have my breather line capped off and a super small hole drilled right thru the top of the reservior cap with the smallest drill bit I could find.

After a DE i might have a little bit of residue in the bucket surround around the cap.

Wil Ferch · 03-02-2011, 08:07 AM

I know the drill when putting in new pads.....not everyone does, so the point being made is that having the normal vent "line" installed is a good thing..... as it serves to limit any damage regardless of whether one was conscious to remove some brake fluid or not.

Howard M · 03-02-2011, 08:43 AM

I simply replaced the entire drian line with a shorter version in the shape of a kitchen sink trap. I snaked a coat hanger wire into the rubber line so it would keep it's shape and I stuck some cotton in the open end as a filter. Works fine.