4x4 front disc brake swap grief

[jeffspower]

I've been wanting to change out the '68 4x4 front drum brake closed knuckle front axle to a later disc brake front for over 25 years now... and I'm finally getting 'round toit. A '75ish axle is bolted in with calipers and hoses for that year, this stuff is about the same as what is on my '72. No problems that can't be overcome (yet anyway) with the '71 K10 booster, MC and proportioning valve I'm putting on also. Where I ran into problems is the front hard lines I robbed from what I thought was a '71 K10. It must have been a '70 converted to disc brakes, as the hoses were in the front frame holes (now that I think back on it) and the lines are bigger, so they won't attach to my hoses. I have no problem bending up some lines the correct size, but I'm sure the special banjo fitting & bolt at the LF hose won't be available locally. I'll probably have to find a tee. I know a complete set of lines from Inline Tube would probably be the best, but it's money I don't have right now and need to get this truck going.

Does anyone know if the front drum brake residual check valve is in the MC, or prop. valve? I'm thinking it is in the MC- which would be nice, as it would be a tad easier to use the old prop. valve.

What a pain!

[JimKshortstep4x4]

Drum brakes don't have a proportioning valve. The disc/drum brakes like on the 71 and up have to have a proportioning valve so that the front and rear brakes are equalized.

Drum brakes have distribution valves
but not proportioning valves so you will need one.

On my son's 70 when we swapped out the drum for disc axles, we located the hole in the frame for the 71 brake hose location. On the 71-72's the fittings used are line fittings and are not special like the original setup. We also went with the smaller 3/16" line as the disc setups were equipped with.

Jim

Jim

[Rack Man]

My 70 (K-10) with drums had them in the front frame holes from the factory......I ordered all new SS lines from Inline Tube for my conversion and EVERY single piece was wrong!....After about 4 months of nightmare I got mine completed....I will NEVER use Inline Tube ever again....Their customer service is an absolute joke!

I wound up using the stock 70 location for all of the hard lines and then went down to my local hyraulic hose guy and had him make me up the soft lines in the correct length with the proper fittings....I brought him the soft lines that were wrong (From I.T.) and he re-used the banjo fittings from them when he made up my new ones......

[jeffspower]

Originally Posted by Rack Man

My 70 (K-10) with drums had them in the front frame holes from the factory......I ordered all new SS lines from Inline Tube for my conversion and EVERY single piece was wrong!....After about 4 months of nightmare I got mine completed....I will NEVER use Inline Tube ever again....Their customer service is an absolute joke!

I wound up using the stock 70 location for all of the hard lines and then went down to my local hyraulic hose guy and had him make me up the soft lines in the correct length with the proper fittings....I brought him the soft lines that were wrong (From I.T.) and he re-used the banjo fittings from them when he made up my new ones......

I have the luxury of using either hole... stock hoses were too short with my appx. 2-1/2" lift, so I had some made down at the local hydraulic hose shop too. They had the correct ends & all- so I had them made 6" longer than stock. Plenty long to use either hole. Pricey though, $120 for the pair! One of the reasons I don't have the cash for made-to-order hard lines. Which, as you stated and I have heard from others, might not work out either.

Originally Posted by JimKshortstep4x4

Drum brakes don't have a proportioning valve. The disc/drum brakes like on the 71 and up have to have a proportioning valve so that the front and rear brakes are equalized.

Drum brakes have distribution valves
but not proportioning valves so you will need one.

On my son's 70 when we swapped out the drum for disc axles, we located the hole in the frame for the 71 brake hose location. On the 71-72's the fittings used are line fittings and are not special like the original setup. We also went with the smaller 3/16" line as the disc setups were equipped with.

Jim

Jim

Never thought about the prop/ dist differences. I knew that at one time along time ago. I guess my memory is fading

I looked at the OE lines on my '72 a little closer. The front lines join with a tee inside the frame just behind the steering gearbox. If someone in town has a 3/16" tee, it might not be so tough to make work after all. The MC & prop. valve are identical on it to my "71 donor" parts... so it makes me wonder if I ordered Inlines kit for a '72 shortbox K10 if they would fit right. I don't see a reason they wouldn't, unless they don't get them right.

Thanks for the help

[jeffspower]

This should give everyone a chuckle. I had a '64 K20 on 38" swampers years ago. Drum front, single piston master cylinder and a '72 power booster. When I put a disc brake front end in it, I hooked up the system "as is" so I could move it around until I rounded up the correct parts. They worked great! Bias was perfect, even on ice. More stopping power and a better pedal feel than any truck I've ever had! So I left it that way & drove it for years.

[BLAZERMAN]

Jeff, I have a complete front brake tube loop here that I saved off a 72 Blazer...I believe its complete all the way to the prop valve and I even have a few of those if you need one.

[jeffspower]

Originally Posted by BLAZERMAN

Jeff, I have a complete front brake tube loop here that I saved off a 72 Blazer...I believe its complete all the way to the prop valve and I even have a few of those if you need one.

That would be sweet! PM me your # so I can call, or let me know what evenings you might be around this week.

Thanks
Jeff

[BLAZERMAN]

Sent you a PM

[duallyjams]

Originally Posted by jeffspower

This should give everyone a chuckle. I had a '64 K20 on 38" swampers years ago. Drum front, single piston master cylinder and a '72 power booster. When I put a disc brake front end in it, I hooked up the system "as is" so I could move it around until I rounded up the correct parts. They worked great! Bias was perfect, even on ice. More stopping power and a better pedal feel than any truck I've ever had! So I left it that way & drove it for years.

Some times you just never know what will work.