Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (http://www.hotrodders.com/forum/)
-   Hotrodding Basics (http://www.hotrodders.com/forum/hotrodding-basics/)
-   -   Wheel cylinders (http://www.hotrodders.com/forum/wheel-cylinders-226760.html)

Oilyrascal 12-03-2012 03:54 AM

Wheel cylinders
 
Have any of you guys heard of any problems with honing out wheel cylinders too far other than leaking.

Here is my story, when I purchased the truck it had no brakes, after my upgrade with modern drivetrain I used the 1986 F-250 power brake booster and master cylinder and ran all new lines.

The original wheel cylinders are UN-obtainable except thru a select group of guys that swiped up all of the left over Napa stock, they now want 90 dollars a piece for them which is the same amount Apple hydraulics and some of the others want to rebuild them with S.S. I have 6 of them in the truck and this amounts to alot of money for me.

I removed the originals and honed them out, they were rusty and pitted, when I say honed I mean bore maybe. I sat there with a bucket of water ( or oil, cant remember what I used ) and went thru 3-4 of the small drill driven honing tools you would find at Napa. I sat there for hours, I never did get rid of all of the pitting but they looked alot better.

I was able to purchase new kits to put them back together and did this.

I bled the brakes and never had a leak but also never had much of a pedal, if I pumped it once or twice than all was well but on first stomp of the pedal it usually went nearly to the floor.

I adjusted the brakes time and again according to the procedure given in the service manual.

The original 52 F-7 Ford braking system used a large booster mounted up under the floorboards.

All I did was mount the 86 booster/master cylinder on the firewall and run new lines down to each wheel, no proportioning valve anywhere just straight lines to the cylinder, one T in the front and one T in the rear.

I am fixin to get to the point of doing the brakes again and would prefer again to not spend the 90 dollars to get these correct wheel cylinders but want this to be done with.

I have heard that the F-7s are notorious for being hard to bleed, I bled them and bled them and bled them a few more times, I tried this over and over again.

I have never been able to figure out whey I did not have a pedal. Any input would be appreciated.

poncho62 12-03-2012 04:54 AM

You need a proportioning valve.....Plus, that 86 MC is made for disk brakes on front.

As for the wheel cylinders, if they are not leaking and they push out the brake shoes, they are good.

Irelands child 12-03-2012 06:08 AM

That '86 MC just may not be moving enough fluid. With that said, remember that brake fluid is virtually non compressible and that all you are doing in effect is moving a solid that can go around corners to push something flexible out. I believe that what you have are two opposing wheel cylinders (Lockheed brakes) in the rear similar to what Chrysler used for many years - and were less then great. If you need 3 oz to move the wheel cyls out and are only moving 2 oz ..... You have said that the replacements are in the $90 range - and that others have cornered the market. If indeed these are opposing wheel cylinders, look at the various, at least through the '50 and possibly further if I recall, choose one that is close in size and give it a try - I use Rock Auto Parts for my search.

oldbogie 12-03-2012 12:51 PM

Quote:

Originally Posted by Oilyrascal (Post 1618453)
Have any of you guys heard of any problems with honing out wheel cylinders too far other than leaking.

Here is my story, when I purchased the truck it had no brakes, after my upgrade with modern drivetrain I used the 1986 F-250 power brake booster and master cylinder and ran all new lines.

The original wheel cylinders are UN-obtainable except thru a select group of guys that swiped up all of the left over Napa stock, they now want 90 dollars a piece for them which is the same amount Apple hydraulics and some of the others want to rebuild them with S.S. I have 6 of them in the truck and this amounts to alot of money for me.

I removed the originals and honed them out, they were rusty and pitted, when I say honed I mean bore maybe. I sat there with a bucket of water ( or oil, cant remember what I used ) and went thru 3-4 of the small drill driven honing tools you would find at Napa. I sat there for hours, I never did get rid of all of the pitting but they looked alot better.

I was able to purchase new kits to put them back together and did this.

I bled the brakes and never had a leak but also never had much of a pedal, if I pumped it once or twice than all was well but on first stomp of the pedal it usually went nearly to the floor.

I adjusted the brakes time and again according to the procedure given in the service manual.

The original 52 F-7 Ford braking system used a large booster mounted up under the floorboards.

All I did was mount the 86 booster/master cylinder on the firewall and run new lines down to each wheel, no proportioning valve anywhere just straight lines to the cylinder, one T in the front and one T in the rear.

I am fixin to get to the point of doing the brakes again and would prefer again to not spend the 90 dollars to get these correct wheel cylinders but want this to be done with.

I have heard that the F-7s are notorious for being hard to bleed, I bled them and bled them and bled them a few more times, I tried this over and over again.

I have never been able to figure out whey I did not have a pedal. Any input would be appreciated.

Did you bleed the master cylinder? This is a separate and messier function from bleeding the wheel cylinders. When there is air trapped inside the master's piston the braking will be minimal at best. Additionally, the 86 master is for disks up front which use very little fluid to actuate compared to drums.

Bogie

vinniekq2 12-03-2012 12:58 PM

all of the above plus you can power bleed the system if you think you and your bleed partner are missing some air. do it twice.Make sure fluid is coming out clean before you tighten bleeder.
You can also use your finger over bleeder opening to prevent air being drawn back in if you must bleed with out power bleeder and you are not sure about partner lifting the pedal too quickly.

Oilyrascal 12-03-2012 03:32 PM

Quote:

Originally Posted by poncho62 (Post 1618463)
You need a proportioning valve.....Plus, that 86 MC is made for disk brakes on front.

As for the wheel cylinders, if they are not leaking and they push out the brake shoes, they are good.

Can you elaborate as to why I need a proportioning valve, the original set-up in the 86 did have one, I have considered this all along as a possibility to a problem and have posed this very same question on other forums and the suggestion of needing one has been blown off.

I have also considered the master as being an issue because as you say it was made for disks up front, again I have suggested this very same question to others and have been blown off. Please elaborate if you can.

I know what a proportioning valve does, just trying to understand why I may need one here.

Oilyrascal 12-03-2012 03:38 PM

Quote:

Originally Posted by Irelands child (Post 1618473)
That '86 MC just may not be moving enough fluid. With that said, remember that brake fluid is virtually non compressible and that all you are doing in effect is moving a solid that can go around corners to push something flexible out. I believe that what you have are two opposing wheel cylinders (Lockheed brakes) in the rear similar to what Chrysler used for many years - and were less then great. If you need 3 oz to move the wheel cyls out and are only moving 2 oz ..... You have said that the replacements are in the $90 range - and that others have cornered the market. If indeed these are opposing wheel cylinders, look at the various, at least through the '50 and possibly further if I recall, choose one that is close in size and give it a try - I use Rock Auto Parts for my search.

Not moving enough fluid is a possibility, I would not know how to tell though. The original master was if I remember correctly a little dinky thing but I guess in this case maybe size does not make much of a difference.

The wheel cylinders are real strange in how they fit into the backing plate, they are un-like anything I have ever seen. I have poured over Napa catalogs loaned to me from a Napa friend and have found nothing like them.

I guess I could modify anything to work but I have to figure the time it would take to do so.

What do you think about the post made by Poncho, the front reservoir is much smaller and that is the one that fed the disks originally. Also the proportioning valve deal makes sense.

Oilyrascal 12-03-2012 03:43 PM

Quote:

Originally Posted by oldbogie (Post 1618611)
Did you bleed the master cylinder? This is a separate and messier function from bleeding the wheel cylinders. When there is air trapped inside the master's piston the braking will be minimal at best. Additionally, the 86 master is for disks up front which use very little fluid to actuate compared to drums.

Bogie

No I did not bleed the master, I have never done this when I have swapped a master from one vehicle to another. I guess I should have. I will be needing to buy a new power brake booster and master cause they have become ruined in the rain sitting outside. I will bleed the master for sure.

Can you elaborate on the master size issue as well, again I have posed all of these questions on another forum and I am amazed that you guys have had so much to say that actually is making sense and helping.

Oilyrascal 12-03-2012 03:45 PM

Quote:

Originally Posted by vinniekq2 (Post 1618616)
all of the above plus you can power bleed the system if you think you and your bleed partner are missing some air. do it twice.Make sure fluid is coming out clean before you tighten bleeder.
You can also use your finger over bleeder opening to prevent air being drawn back in if you must bleed with out power bleeder and you are not sure about partner lifting the pedal too quickly.

I did bleed many time with a power bleeder. I am wondering though if air was being drawn in around the threads of the nipple, I wonder if teflon tape would hold up against brake fluid and seal those threads?

alkey 12-03-2012 04:33 PM

brakes
 
you said after you pump the brakes all is well.are you sure you have brakes adjusted properly

Oilyrascal 12-03-2012 05:52 PM

Sure as I can be, I am doing what the service manual says to do, seem to adjust much like any other older vehicle, adjust them out till they rub and then back them off a little.


All times are GMT -6. The time now is 06:23 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.