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Help - Brake Distribution Block Leaks at Switch Port

  • Thread starter Thread starter 65-Fstbk
  • Start date Start date Feb 10, 2021
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65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 10, 2021
#1
  • Feb 10, 2021
  • #1
Hey All,

I am having issues with the brake distribution block leaking at the switch when bleeding the brakes.
I did a front drum to disc conversion, switched to a dual bowl master and did the plumbing.

I started with a Circa 1970 original distribution block - leaked at switch port when bleeding
I heard that placing a pin-stopper in the switch port prevents the piston from moving when bleeding so I tried that
Still leaked at switch port (fluid should not get to this area)
So I bought a rebuild kit and rebuilt the block - still leaked at switch port
Took it apart, checked everything and remounted it 3 times and 3 times it still leaked at switch port
I also confirmed with the company that sells the rebuild kit that my gaskets etc were all in the correct orientation
Finally gave up on that and ordered a new distribution block - leaked at switch port (with pin-stopper in)
Company I bought it from sent me a new one - installed that - leaked at switch port

There has got to be a solution for this. I am now thinking of scrapping the block and going with an adjustable proportioning valve that takes both lines from the Master but allows you to dial back pressure to the rear drums once the system is bled. Has that worked for anyone?

Other solutions?

Thanks Guys
 

wicked93gs

15 Year Member
Sep 30, 2006
1,198
228
93
Nashville TN
Feb 10, 2021
#2
  • Feb 10, 2021
  • #2
Damaged threads on the actual switch itself?
 
Reactions: 2Blue2

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 11, 2021
#3
  • Feb 11, 2021
  • #3
wicked93gs said:
Damaged threads on the actual switch itself?
Click to expand...
Thanks but can't be that b/c the new blocks came with new switch. The thing is, brake fluid should not get to that area, it should be staying dry even if the internal piston shifts to one side under a pressure loss situation. This seems to be a pretty common problem but no-one seems to have a concrete solution.
 

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 11, 2021
#4
  • Feb 11, 2021
  • #4
My 2 cents

Leaks at the plastic right?
70 P-block

Lower Right corner picture switch slides to the fitting and stops.
Wrong fitting then switch slides to far and leaks


 

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 11, 2021
#5
  • Feb 11, 2021
  • #5
maybe post a picture of it
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 11, 2021
#6
  • Feb 11, 2021
  • #6
2Blue2 said:
maybe post a picture of it
Click to expand...
I've got a short video clip (from my phone) but this website doesn't accept the file extension. I have uploaded to YouTube and placed a link here.
View: https://youtu.be/DoDrYe_kSls

Hopefully this works.
Note I have tried this many times, rebuilt the block, new blocks, with switch in place with the green pin stop in place. They ALL leak.
 

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 12, 2021
#7
  • Feb 12, 2021
  • #7
Which kind brake fluid you useing?
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 12, 2021
#8
  • Feb 12, 2021
  • #8
2Blue2 said:
Which kind brake fluid you useing?
Click to expand...
Standard DOT 3
 

wicked93gs

15 Year Member
Sep 30, 2006
1,198
228
93
Nashville TN
Feb 12, 2021
#9
  • Feb 12, 2021
  • #9
What is your brake line pressure?
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 12, 2021
#10
  • Feb 12, 2021
  • #10
wicked93gs said:
What is your brake line pressure?
Click to expand...
Hmmmm, I haven't checked that. Wouldn't think anything surprising b/c it's just a manual disc/drum setup with a new dual bowl master.
 

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 13, 2021
#11
  • Feb 13, 2021
  • #11
You got fluid coming out all 4 bleeders?
Just a guess, but for so many attempts to fail, there must be rubbish/ rust in the old lines thats damaging the o rings?
But with the pin stopper you would think the o-rings are not rubbing yet...

If they sent a new one without getting old one back makes you think they have had this problem before.
Just maybe you got a damaged original followed by a couple pf crappy replacements?

This is your second thread on this right?
Other than that I aint got nothing.
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 13, 2021
#12
  • Feb 13, 2021
  • #12
I have purchased an adjustable prop valve. I'll let you know how it goes.
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 13, 2021
#13
  • Feb 13, 2021
  • #13
2Blue2 said:
You got fluid coming out all 4 bleeders?
Just a guess, but for so many attempts to fail, there must be rubbish/ rust in the old lines thats damaging the o rings?
But with the pin stopper you would think the o-rings are not rubbing yet...

If they sent a new one without getting old one back makes you think they have had this problem before.
Just maybe you got a damaged original followed by a couple pf crappy replacements?

This is your second thread on this right?
Other than that I aint got nothing.
Click to expand...
All the lines are new.
It has me perplexed and it seems this problem is not that unusual.
I have tried and original 1970 era block and that leaked,
I rebuilt it 3 times and had the rebuild guy confirm my seal placement was correct - leaked 3x
I bought a new block - leaked
I installed a replacement new block - leaked
If this new block leaks you may see the car on Craigslist. LOL
 

wicked93gs

15 Year Member
Sep 30, 2006
1,198
228
93
Nashville TN
Feb 14, 2021
#14
  • Feb 14, 2021
  • #14
65-Fstbk said:
Hmmmm, I haven't checked that. Wouldn't think anything surprising b/c it's just a manual disc/drum setup with a new dual bowl master.
Click to expand...

I ask because its remotely possible that for some reason the pressure is higher that what the o-rings are able to stop. I couldn't say why that would be...but its the only thing I can really think of...unless the o-rings are simply too small or you have had a run of bad brake switch blocks
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 16, 2021
#15
  • Feb 16, 2021
  • #15
Over the weekend I purchased an adjustable proportioning valve that accepts both front and rear lines. I had to do some replumbing of the lines and fab a homemade bracket but got it in. So far no leaks.

BTW - If anyone needs to run double flares on brake lines I would highly recommend the Titan tool. I have no financial incentive, no freebies etc but the tool worked way better than those typical flare kits. If anyone wants me to post a pic of it let me know. Nice to use a tool that works nicely.
 
Reactions: 2Blue2

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 17, 2021
#16
  • Feb 17, 2021
  • #16
65-Fstbk said:
So far no leaks.
Click to expand...
Yea! Problem solved.
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 17, 2021
#17
  • Feb 17, 2021
  • #17
Fingers crose
2Blue2 said:
Yea! Problem solv
Click to expand...
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 17, 2021
#18
  • Feb 17, 2021
  • #18
Fingers crossed. It's in for paint as of this morning.
 
Reactions: 2Blue2

2Blue2

will be trying this sex one when I can find it
Mod Dude
Mar 5, 2019
4,430
2,893
163
Oahu
Feb 19, 2021
#19
  • Feb 19, 2021
  • #19
Drum roll please!
Final color is?
 

65-Fstbk

15 Year Member
May 20, 2007
316
26
49
Vancouver, B.C. Canada
Feb 19, 2021
#20
  • Feb 19, 2021
  • #20
2Blue2 said:
Drum roll please!
Final color is?
Click to expand...
I still have a few days to decide but I am really thinking Chalk with Graphite grey Shelby/rocker striping.
 
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