im putting discs all around my bug what master should i use?

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Clatter
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Post by Clatter » Sat Mar 28, 2009 3:01 pm

Kuleinc,
Check to see that your rear flex hosess have not collapsed internally...
That one just got me a week or two ago.
They looked OK on the outside, completely blocked inside....
"Oh, You don't need to do all that... The valve seats are just going to fall out of it anyway!"
- Doug Ellsworth

Beginners' how-to Type 4 build thread ---> viewtopic.php?f=1&t=145853

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kuleinc
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Post by kuleinc » Sun Mar 29, 2009 3:58 pm

The bolts are grade 8 3/8 bolts

They are not metric, the plates that the calipers bolt to were apparently drilled for US bolts, not metric, so they are grade 8 US.

Also, how important is it on late model dual piston gia calipers that those half shims be there, as I think they're making the brakes squeak like mad, and I took them out, and no squeaking, but a bit lower pedal....
1995 BMW 318ti with M3 Motor (Mine)
1994 BMW 325i Sedan (Hers)
1968 Baywindow Camper (Parts Bus)
1971 Westy Baywindow (EFI project...)
My build thread: viewtopic.php?f=14&t=137593

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FJCamper
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Pad Shims

Post by FJCamper » Sun Mar 29, 2009 5:50 pm

Hi Kuleinc,

The VARGA caliper brake pad shims are supposed to stop pad vibration and squeal.

We run without them on our cars, but they are track only. No apparent affect on pedal travel for us.

FJC

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kuleinc
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Post by kuleinc » Sun Mar 29, 2009 9:24 pm

Awesome, car seems to be stopping pretty decent now. I'm not too thrilled with the low pedal due to disks, it goe shalf way to the floor under normal brakeing....

Would a porche M/C push more fluid and firm up such a soft pedal?
1995 BMW 318ti with M3 Motor (Mine)
1994 BMW 325i Sedan (Hers)
1968 Baywindow Camper (Parts Bus)
1971 Westy Baywindow (EFI project...)
My build thread: viewtopic.php?f=14&t=137593

Bruce2
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Post by Bruce2 » Sun Mar 29, 2009 9:49 pm

kuleinc wrote:Awesome, car seems to be stopping pretty decent now. I'm not too thrilled with the low pedal due to disks, it goe shalf way to the floor under normal brakeing....

Would a porche M/C push more fluid and firm up such a soft pedal?
If you use a MC with a bigger bore to deliver more fluid, your pedal effort goes up just as much.

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kuleinc
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Post by kuleinc » Sun Mar 29, 2009 9:52 pm

The pedal effort is currently, zero, I can push it to the floor if I want, but I don't need to to stop...

I just don't like how disks feel with manual brakes I guess...

Used to it being so firm and solid with drums all around, but I got tired of there not being any stopping power at the bottom of hills. I have to drive up and down hills to get to work and school...

It stops great now, but the pedal is so soft, I dunno, maybe it will grow on me...

the first master was definitely bad.
1995 BMW 318ti with M3 Motor (Mine)
1994 BMW 325i Sedan (Hers)
1968 Baywindow Camper (Parts Bus)
1971 Westy Baywindow (EFI project...)
My build thread: viewtopic.php?f=14&t=137593

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FJCamper
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Pedal feel

Post by FJCamper » Mon Mar 30, 2009 2:48 pm

Hi Kuleinc,

Yes, 4-wheel non-power disks can feel different from drums or disk-drum. My advice comes from our experience. We have one 4-wheel disk racer and one disk-drum.

Pedal feel on drums comes from shoe travel. A brake adjustment made the pedal feel high and hard. The same was true of disk-drum.

Disks are "self-adjusting" but can have a different feel because the pads move back and forth a little with each brake application. You get a more positive pedal feel with a 19mm master cylinder. The larger cylinders have a softer feel.

A residual pressure valve for the rear brakes will help.

FJC

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kuleinc
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Post by kuleinc » Mon Mar 30, 2009 3:17 pm

even if I have rear drum? and if so, what size residual valve for the rear? I hear this also helps with the longevity of the wheel cylinders...
1995 BMW 318ti with M3 Motor (Mine)
1994 BMW 325i Sedan (Hers)
1968 Baywindow Camper (Parts Bus)
1971 Westy Baywindow (EFI project...)
My build thread: viewtopic.php?f=14&t=137593

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FJCamper
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Residual valve

Post by FJCamper » Tue Mar 31, 2009 8:35 am

Hi -

The residual valve is for rear disks. You don't need it with rear drums.

the valve keeps the pads slightly touching the disk, so less pedal is necessary to apply the brakes.

FJC

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mlski67
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Post by mlski67 » Mon Apr 06, 2009 8:22 pm

I have a prob with my 4 wheel disc breaks. when i drive my car and the launch it hard or drive it around the break light comes on and the breaks drag/ lock.. it builds break prex up and goes away after a few min of sitting . I thought the lines where getting hot re routed and wrapped still nothing i am running a duel master cyl from cb perf it has a little scew on the top not sure what it is says they are fro disc breaks.. it seem that mainly the back breaks are locking up. also my car is really low if that helps. any advice ? thanks

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kuleinc
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Post by kuleinc » Mon Apr 06, 2009 9:56 pm

Check your pedal freeplay, it sounds like maybe the master cylinder isn't getting to the top of the travel...
1995 BMW 318ti with M3 Motor (Mine)
1994 BMW 325i Sedan (Hers)
1968 Baywindow Camper (Parts Bus)
1971 Westy Baywindow (EFI project...)
My build thread: viewtopic.php?f=14&t=137593

Bruce2
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Post by Bruce2 » Tue Apr 07, 2009 1:31 am

mlski67 wrote:I have a prob with my 4 wheel disc breaks. when i drive my car and the launch it hard or drive it around the break light comes on and the breaks drag/ lock.. it builds break prex up and goes away after a few min of sitting . I thought the lines where getting hot re routed and wrapped still nothing i am running a duel master cyl from cb perf it has a little scew on the top not sure what it is says they are fro disc breaks.. it seem that mainly the back breaks are locking up. also my car is really low if that helps. any advice ? thanks
First, you need to check your spell check so we can understand what the heck you're trying to say.

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mlski67
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Post by mlski67 » Tue Apr 07, 2009 4:43 am

Bruce2 wrote:
mlski67 wrote:I have a prob with my 4 wheel disc breaks. when i drive my car and the launch it hard or drive it around the break light comes on and the breaks drag/ lock.. it builds break prex up and goes away after a few min of sitting . I thought the lines where getting hot re routed and wrapped still nothing i am running a duel master cyl from cb perf it has a little scew on the top not sure what it is says they are fro disc breaks.. it seem that mainly the back breaks are locking up. also my car is really low if that helps. any advice ? thanks
First, you need to check your spell check so we can understand what the heck you're trying to say.
well thanks for your help i do know my typing is bad and don really care to know that it is thanks for being a smart ass it must not be to bad the other guy understood me and gave me some helpful advice.. thanks for your waste of time comment

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FJCamper
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Rear lockup

Post by FJCamper » Tue Apr 07, 2009 8:03 am

Hi mlski67,

I don't know if you have parking brakes on your rear disks -- which could change my long distance diagnostic.

It sounds like for some reason, your brake master cylinder internal pressure relief valve is not bleeding down right and residual pressure is keeping the rear brakes applied.

The screw on the top of the master cylinder is for disassembly of the cylinder. It is a stop for the internal piston. If the screw has been loosened and retightened the piston travel has been affected, you could easily get pressure problems.

This is a lot of work, but your brakes are vital. Remove the master cylinder, and carefully disassemble it. You'll see how that screw works. It holds the piston in place.

Put it all back together, checking for full piston stroke.

This is very likely your problem. Not much else besides bad rear flex lines can impede pressure.

FJC

Bruce2
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Post by Bruce2 » Tue Apr 07, 2009 9:16 pm

mlski67 wrote:
Bruce2 wrote:
mlski67 wrote:I have a prob with my 4 wheel disc breaks. when i drive my car and the launch it hard or drive it around the break light comes on and the breaks drag/ lock.. it builds break prex up and goes away after a few min of sitting . I thought the lines where getting hot re routed and wrapped still nothing i am running a duel master cyl from cb perf it has a little scew on the top not sure what it is says they are fro disc breaks.. it seem that mainly the back breaks are locking up. also my car is really low if that helps. any advice ? thanks
First, you need to check your spell check so we can understand what the heck you're trying to say.
well thanks for your help i do know my typing is bad and don really care to know that it is thanks for being a smart ass it must not be to bad the other guy understood me and gave me some helpful advice.. thanks for your waste of time comment
Not being a smart-ass at all. Just pointing out your illegible typing style prevents people from understanding what's going on. The fact that you know your post is poorly written says you don't have any consideration for everyone attempting to read it.
Good luck with your problem.

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