1968(or later) brake setup problems in my '65 c10

[Woogeroo]

The master brake cylinder in my '65 c10 is a 1968 or later chevrolet unit. I'm having issues around the MC at the moment. That is why I am posting this in the 67-72 forum. If this needs to be moved, I apoligize... and please to move it to the more appropriate forum.

-W

------ The Post ------


The problem I'm having right now is a lack of good pedal after bleeding my brakes on my 1965 c10 lwb stepside.

However, there were some things that led up to this problem, so here are the juicy details.

Yes this is a long post, but I think I need to give out all of the details if I'm going to find out what is going on.


Within this post:


MC = master brake cylinder



A little needed information before we get started:

The master cylinder in my '65 c10 is a dual pot(reservoir) master brake cylinder with the vacuum booster... which was not an option in 1965 as far as I know. I have been told previously by people who have seen pictures of my engine compartment or who have seen it in person that the MC was a 1968 or later model chevrolet unit. This unit was in the truck when I bought it in April 2003, until today, I have had issues with it.


Here is a picture of the MC from a few days ago before this grand adventure began:

http://woogeroo.home.mindspring.com/...262006/17.html


My truck has the stock 1965 style drum brakes all the way around. New pads and a lot of the internal drum hardware within the past 6 months.


--- The beginning of how all of this got started ---

This particular adventure all got started when this part(electric trailer brakes control box) here started leaking(brake fluid) inside the cab from out of the box unit itself, so I decided it was time for it to go.


For an image and details of the unit, go here:

Under dash box for electric trailer brakes

http://woogeroo.home.mindspring.com/...142003/28.html


----


So, the trailer brakes unit had an actual brake line that was running from the bottom of the box in this picture:

http://woogeroo.home.mindspring.com/...s/brakes02.jpg

This box is all tied in with the master brake cylinder. The line on the bottom, right with all the brake fluid on it. There was a brass T-fitting that the line that goes to the trailer brake unit box went into that has already been removed in this picture.

----

So, I removed the line and the brass T-fitting... and reinstalled the brake line and made everything snug. So, I figured I should bleed the brakes for good measure. Start at the rear passenger wheel... and then the other side, then the passenger side front, then the driver side front.

So, I start doing that... pump it up, hold, bleed(my dad was helping on the pumping up part). On the rear, everything went fine... when ya cracked the bleeder valve open, the brake pedal would go down to the floor.

When we got to the front and started cracking open the bleeder valves on the wheels, we started getting issues with the pedal being already down and having 'no pedal feel'. We tried bleeding them a few more times ,but very little fluid would come out, with little pressure behind it.

Right about this time we were '$#@!#$@%#@?!???'

So, we were like... hmn, the master brake cylinder didn't go out all at once while we were standing here did it? We added checked stuff, tried bleeding some more, same result... great pedal bleeding the back... no joy doing the front.

Well, I say hmnn... mebbe the master brake cylinder is whack. Maybe I should just replace it.


----

Now, the master brake cylinder that I took off is this one:


http://woogeroo.home.mindspring.com/...s/brakes05.jpg



The only casting number that I found on it is this:

T48 5452810
3

The 8 may be a 3... it was hard to read.

----


So I took that off and went on a interesting adventure at NAPA trying to look one up... and found one at another store.

----

The new Master Brake Cylinder:


http://woogeroo.home.mindspring.com/...s/brakes08.jpg


In the NAPA super computer, this master brake cylinder is for a 1969 chevrolet c10 1/2 ton - stock number: TS 10-1329


The casting number on this one is as follows:

T21 5452310

and on the other side, extra numbers:

C Delco-M C237


-----

I came home, did the bench bleeding thing per the instructions... hooked the lines back up. Filled up the reservoirs with fluid, put the top back on and we back to pumping it all up. Again, I started at the rear passenger wheel... and then the other side, then the passenger side front, then the driver side front.

So, again the rear wheel brakes are getting good strong pedal feel when we bleed them.

The front wheels are not squirting out fluid like they should, plus the pedal is not strong at all, to the poitn of having to pull the brake pedal back up with your foot.



-----

I think the MC is the same, it is the same length, same fittings, same shape... etc.. I could be wrong though, maybe there is some subtle and important functional difference.

I'm wondering if maybe this part(links to images below) is malfunctioning or if it needs to be different or 'adjusted' somehow since the trailer brake unit box is no longer connected?


http://woogeroo.home.mindspring.com/...s/brakes02.jpg <- with the MC uninstalled


http://woogeroo.home.mindspring.com/...s/brakes08.jpg <-- with the new MC installed

I have no idea what the part in the pictures above is.

Does the part in the picture above... is it a chevrolet part or something to do with the trailer brakes unit?

I am at a loss at the moment.


All help is appreciated.

Thank you.

-W



Below is the URL to the folder that all of these pictures are in. If you think it will help to see the rest of the pictures and what not, this is the breakdown of what each picture depicts.


http://woogeroo.home.mindspring.com/...iscimg/brakes/


Index of /Matraca/miscimg/brakes/


MC = Master brake cylinder


Image Index


brakes01 = vacuum booster with the master cylinder off

brakes02 = proportional/proportioning valve / trailer brakes mumbo jumbo?

brakes03 = MC that was removed shot 1

brakes04 = MC that was removed shot 2

brakes05 = MC that was removed shot 3

----

brakes06 = new MC out of the box shot 1

brakes07 = new MC out of the box shot 2

brakes08 = new MC out of the box shot 3

----

brakes09 = new MC installed shot 1

brakes10 = proportioning valve? / trailer brakes mumbo jumbo - up close shot

brakes11 = new MC installed shot 2 (other side)

brakes12 = new MC installed shot 3