Hydrolic brake "spongy"

[DerekF]

I have had a spongy brake on the left side for a couple of months. It is okay (spongy but works) when it is warm out (above freezing), but does not work at all when it is below freezing. Just now getting around to fixing it.

Here is the thing: It is not air in the lines; they have been bled over and over again. I rebuilt the master cylinder a year ago and I assumed I have damaged one of the seals in the install so I replaced the entire master cylinder this week. I was sure this would fix the problem.

Has anyone ever had to replace the seals in the brake cylinders? It is the only thing left to change in the system, so I am assuming it is the problem. Is it a big job?

Derek

Edit: Sorry, should say "Hydraulic Brake Spongy). ???

[plott hound]

i know with cars and trucks bad brake lines will give you a spongy peddle.so i wonder if those short rubber lines would give the same effect if they were begining to rot?

[LarryW]

I would think that if the seal is bad in the brake cylinder it would leak fluid. I am assuming you have an Argo? Maybe plott hound is on to something with the lines.

[racerone3]

Brake lines have cords in them similar to a tire. If one of them breaks, it will allow the line to bubble instead of applying pressure to the pads. Some pad material will also swell when exposed to certain fluids, however I don't think the Argo pads are of a soft material

[runamuk]

Had the same problem with my brake, but the rigth side, rebuilt masters and calipers, found square or quad ring on piston bad on the right side, also make sure the rubber on the top cover of the master is good or it pull air in and make them spongy.

[tizbass]

I had similar problems with my conquest. All I did was clean everything out and put in some new fluid....worked like a charm. The fluid was black from the rubber in the brake lines ...I think. Its the cheapest fix you could try.

[DerekF]

Update,

I changed the master cylinder and the entire brake caliper setup. Lines are bled properly, cap is on the Master cylinder. ??? Still the same problem. I think I must have a brake line that is swelling when I apply pressure, which is ironic because it would have been the cheapest thing to fix in the first place.......

Unfortunately, the dealer can not get a line in for a few days. Can a hose shop make a line for me? Those ends looks different than other hydraulic lines I have seen. In any case, will try to figure something out Monday.

Thanks for the help guys.

D