Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Proportioning Valve - Brake fittings... size? 4w Disks

Discussion in 'The Garage' started by BozoWise, Oct 11, 2005.

  1. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    Does anyone know the size of the factory brake fittings on a 79K5? I am removing the factory PV combination valve and need to add a "T" on the front lines and a adjustable valve on the rear. I found numerous posts on the fittings, valves and such but none of them had an actually size of the lines coming in and out.
     
    Last edited: Oct 12, 2005
  2. danny7139

    danny7139 1/2 ton status

    Joined:
    Jan 27, 2005
    Posts:
    227
    Likes Received:
    0
    Location:
    florida
    just did some work on my lines, granted it is a 88 k5 but they were 3/8 size
     
  3. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    I just got done removing the factory PV and heck dang near all te lines are different sizes. I am going to head off the the parts store and see If I can find a t. The inlet is larger then the 2 outlets on the front lines. The rear line is larger on the outlet side so this might get tricky.

    I was hoping to remove the factory PV and "T" the front lines together and run a adjustabe valve right off the MC for the rear. But I am not sure if I am going to find a reducer/coupler for the rear line. Might be looking at running new rear lines.

    Anyone have a clue? It looks like there has been 100 different ways to do this but not many people have exact measurements or parts listed.
     
  4. thedrip

    thedrip 1/2 ton status

    Joined:
    Dec 13, 2003
    Posts:
    1,129
    Likes Received:
    0
    Location:
    Chattanooga, TN
    All the "skinny" tube (all the front stuff) is 3/16, the single line to the back is 1/4. You can get all the fittings you need at any GOOD parts store, the little tiny checkers and kragens are hurting on brake fitting stuff, I've had the best luck with the big pep boys here, or theres always Napa (the home mechanics stupid mistake saviour).
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,577
    Likes Received:
    945
    Location:
    Massachussetts
    trouble is..

    Your right about the TUBING being 3/16 on the "skinny stuff",and the line to the rear brakes is 1/4"...but the FITTINGS are often "Weird" sizes..many of the Proportioning Valves I had to change brake lines on had 3/16 lines with threaded fittings the same size as what a 1/4 line normally used!..or some other odball thread..

    I often had to save the old fitting by cutting the line and use a 6 point socket to get it off---then cut and re-flare the new line,a big pain in the butt--some parts stores sell brake lines with the 2 different sized fittings on them--but they are few and far between--good luck finding any..

    Some had a strange 9/16x20 machine screw thread on the fittings-,as do many GM master cylinders!--you know,the ones that dont come with that brass adapter dewhickey your old one didn't use--and your changing it on a sunday,when all the "real" parts stores are closed??.. :surepal: :angry1:
     
  6. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    Ok no luck on finding the needed parts, but I did get some measurements.

    The front inlet is 5/16 the two front outlets are 3/16

    The rear inlet is 1/4 but no luck on the outlet size???? It was not 1/4, 3/16, 5/16, or 3/8 which was the only lines they had available at parts store in the po-dunk town of Hobbs.

    I think I might get a PV from a Disk/Disk I found a reference to AC Delco part number 172-1361 which came off a 1980-1994 P30 van. Neither Checker nor Autozone had PV valves for the P30 vans. I wish I could confirm the AC Delco part would bolt up before I drop 100.00 I think this is the part used in the Offroad Unlimited kit below. Now one of the things that concerns me here is that AC Delco lists the 172-1361 as mounted on the front of the brake booster. They also have a 172-1360 that is not listed as mounted on the front of the brake booster :confused:

    Off to do more research. I never thought one of the most frustrating and time consuming parts of this buildup would be the brakes. I should have done them before I got the running gear up since it down blows that I can't go crawling.

    61400-B_large.jpg
     
    Last edited: Oct 11, 2005
  7. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    Ok after a full night of searching and reading posts I came up with a few new part numbers

    The Inline Tube part should be a PR-101 and lists at 99.00

    The GM part number should be a 1257225 and GM parts direct lists them for 40.96

    Can anyone confirm the bolt up fit on these two pieces for a 79 K5?

    I will spend the extra $ to get the inline tube which I have seen confirmed here as bolt up. But why pay twice as much if I can get the GM one to bolt up. It was cross referenced as the above posts P-30 van also. So just two different part numbers for the AC Delco and the GM numbers.
     
  8. Bad Karma

    Bad Karma Registered Member

    Joined:
    Oct 28, 2001
    Posts:
    92
    Likes Received:
    0
    Location:
    Glendale,AZ
  9. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    Thanks for the info I am going to add all the part numbers to the members list once I have confirmation. I went ahead and ordered the GM part before I got your reply. I will confirm or deny if it fits. Figured I would give it a try since it is the least expensive option.

    So we now have confirmation on Bolt Up fit for the inline tube part and yours which I think is the same part.

    1960-87 CHEVY TRUCK PROPORTIONING VALVES #16674 Performance Online
     
  10. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX

    I got this part in today and it is a direct bolt on application including the mounting to my 1979 K5 :D

    pvalve.JPG
     
    Last edited: Oct 21, 2005
  11. BigCountryx

    BigCountryx 1/2 ton status

    Joined:
    Feb 19, 2005
    Posts:
    519
    Likes Received:
    2
    Location:
    Gonzales, LA
    Anybody know what year models these p-valves fit?
     
  12. BozoWise

    BozoWise 1/2 ton status

    Joined:
    Mar 28, 2002
    Posts:
    1,224
    Likes Received:
    0
    Location:
    Lubbock, TX
    1973-80 Chevy Trucks I think the fittings might have changed in 81 because inline tube has a different part number for the 81+
     

Share This Page