The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)

- The 1967 - 1972 Chevrolet & GMC Pickups Message Board (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=3)

- - Part No for Brake Combination Valve (https://67-72chevytrucks.com/vboard/showthread.php?t=820430)

Re: Part No for Brake Combination Valve

Quote:

Originally Posted by dmjlambert (Post 8905749)

Hi, may I ask what does that page come from, and is the book available online as a reference as far as you know?

Once a person knows a part number, are there technical details about the part available, such as measurements or technical drawings?

The reason I'm asking is because on this other thread we are interested in finding the difference between manual and power brakes master cylinder for a 71-72 C-10 pickup (not Longhorn, not C-20, C-30 etc.), such as what is the bore size. http://67-72chevytrucks.com/vboard/s...d.php?t=807819

Those are the charts the brake engineer created in order to release the parts for production and service. They go back to 1969 and were hand written at that point. To my knowledge this is the only remaining copy.

I found out about it during my short tenure as a brake development engineer for truck. I asked if I could borrow it and it somehow never got returned before we all retired.

I thought about having the GM Heritage Center scan it and make copies but I still refer to it on almost a daily basis.

I have the charts for those 71-72 models but am at the races this weekend. I'll check early next week after I settle back in. (You may have to remind me!)

K

Re: Part No for Brake Combination Valve

Thanks Keith, that's interesting and lucky that you have them.

Hoping tomorrow to get at it and try the bleeding tool. Was distracted with other things today.

Quote:

Originally Posted by Keith Seymore (Post 8906375)

Re: Part No for Brake Combination Valve

Quote:

Originally Posted by MARKDTN (Post 8905831)

I am also needing one of these. Those 3 p/ns do not show in any search I have done as remotely available today. Is that the same as Delco 172-1353? There are aftermarket valves available on Ebay and Jegs, but the price varies widely. The interchange appears to be most trucks and big cars like 70s and 80s. Are any of the aftermarket ones any good? Mine (on '83 K20) has the light on, I have pushed and pulled the pin but it does not move. I have a new Delco master cylinder to put on at the same time, but I don't really want to open up the system until I have all the parts to fix it on hand.

Does anybody know if those original p/ns got superseded-perhaps with the one I mentioned? Anybody have good luck with aftermarket, and if so which one? This truck has been in my family since new.

Re: Part No for Brake Combination Valve

Quote:

Originally Posted by dmjlambert (Post 8905749)

Attaching the 71 and 72 brake charts here, and also in the referenced thread.

K

Re: Part No for Brake Combination Valve

Success! Funny now reading the shop manual and following the bleed procedure worked - as you suggested. I was able to get a clamp on the front to stop the pin from coming out and that was it. I’ve now been able to bleed the front brakes and all is well. Thank you all for your assistance!