25mm MC and proportioning valve problem

[LoneWolf]

Was really hoping this would be a quick swap but I've run into some problems.

I used my vacuum bleeder to drain the reservoir, made that part nice and less messy. Mocked in the new MC, line closest to the booster needed some tweaking to line up.

Then I started poking around to try and decide where the proportioning valve should go. I was hoping to put it in place of the stock unit, but hit a snag.

The fittings going into the original proportioning valve are seized. As you know they are in a tight space. Does this mean I should go ahead and get those lines and replace them?

I don't think cutting and splicing those lines would be good or easy to do with how tight it is in there. Should I be thinking they should just be replaced?

I was trying out my double flare kit in preparation of piecing something together.

If I'm going to go through that trouble, how much more would it be to plumb it under the seat?

I'm a little nervous about removing the line from the abs, worried about air getting in there and causing some nagging problems.

[AndrewBird]

Are you using a flare wrench on the lines? If not, try that first. makes a world of difference.

[LoneWolf]

Yeah I am using an actual brake line wrench.

Still not getting enough bite.

Plus down in that area it is super tight, the hard lines turn into the rubber lines right there

[jlevie]

Two types of bias valves were used. One mounts up at the master cylinder, the other mounts on the frame rail pretty much directly below the master cylinder. In this case I'd set the car up with the frame mounted bias valve.

[LoneWolf]

You are correct, the stock valve on my 91 318is is directly below the MC, but I can't get the lines to break free there.

I've been reading a torch on the fitting for a little bit of time can do the job of breaking them free. Seems like a bad idea to stick a torch there, fuel lines right next to it. What do you guys think?

I'm on vacation now so when I get back I have to sort this out.

[jlevie]

Soak the fittings in PBlaster or Kroil for a few days. Then try a flare wrench. If that doesn't work, flame wrench is the next option. Because of the location and the risk of damage to other things you need to use an oxy-acetelyne torch with a 00 tip. That is a small very intense heat source. Even then car is needed.

Or you can cut the lines and use new ones after.

[SmokeE30]

I just delt with this, it is tight down there but I managed to get it by moving the fuel lines and filter out of the way and getting a line wrench on the lower line and a regular box end 7/8 i belive on the valve itself to hold it steady to break it loose. Whoever decided where to place the brake line fittings in e30s was not a technician or a fan of us lol

[Smelser]

I just delt with this, it is tight down there but I managed to get it by moving the fuel lines and filter out of the way and getting a line wrench on the lower line and a regular box end 7/8 i belive on the valve itself to hold it steady to break it loose. Whoever decided where to place the brake line fittings in e30s was not a technician or a fan of us lol

as wit most car designers. I assume they had unhappy childhoods and are punishing the rest of the world!

[LoneWolf]

I'm going to give it a good soak and try getting my hands in with another wrench to how it still.

What can I use to seal where the line enters the interior? Anyone with a good body grommet I could modify to seal around the entering and exited brake lines?

I have decided with all this trouble I may as well find a way to mount it in the cabin to make adjustments simple.

[e30topdown]

Don't worry about breaking apart lines from the ABS unit. I had to replace the line to the left front wheel well from the ABS. I sweated about opening up the line at the ABS. I did stub the ABS opening while changing out the lines. Bentley says to make sure you pump the brake pedal 12 times before bleeding that new line. This pushes any air in the ABS unit up into that line. Bleeding was short and sweet. My 93 vert has the valve on the frame. Decent location, if you want to make a change.

[LoneWolf]

Don't worry about breaking apart lines from the ABS unit. I had to replace the line to the left front wheel well from the ABS. I sweated about opening up the line at the ABS. I did stub the ABS opening while changing out the lines. Bentley says to make sure you pump the brake pedal 12 times before bleeding that new line. This pushes any air in the ABS unit up into that line. Bleeding was short and sweet. My 93 vert has the valve on the frame. Decent location, if you want to make a change.

Thanks for the input, I was really nervous about pulling the line right at the abs unit.

[LoneWolf]

So I have made some progress.

After a lot of wrestling and standing on my head I was able to get the MC installed and the new proportioning valve. I plumbed the valve in right by the MC.

New problem.

Went to bleed the brakes. I assumed the rear pads would need replaced because the MC seemed to only be giving me rear brakes.

Well after putting new pads on the passenger side and bleeding that line I moved to the drivers side. There I found pads that looked hardly used.

When I tried compressing the piston it did not want to budge. I then pressed on the pedal a bit to get it to come out. But it will not compress.

I need to replace the drivers side caliper correct?

Weird thing is I never felt the car pull. Any way I can test the passenger side caliper?

Thanks

[LoneWolf]

Well.....

I think both rear calipers are toast. The one felt seized, could not compress piston back in. The passenger side, one that completely had the pads eaten off seemed to be sticking on. After pressing the pedal the caliper seems to stay clamped. Probably what ate the pads.

Was able to get one caliper today, other will be in tomorrow at 8 am.

Maybe someday this brake adventure will be over.

[LoneWolf]

Finished the swap. Two new rear calipers later.

Dialed in the proportioning valve. Feels good, stops hard.

Pedal is more firm I like it. Really just glad my brakes are back to normal.

Now on to the suspension, then bbk time.