Quick poll on brake overhaul

[RangerDave]

After a brake failure during a routine pre-trip inspection, I elected to overhaul the whole system....

So far I have pulled the Master Cylinder and Airpack - All gunked up. It was amazing that I only had a minor symptom of a hard brake pre failure (occurred twice) - airpack problem... and there was at least the entire M/C volume of brake fluid inside when I pulled it apart.... I am assuming the airpack failed internally because I could not locate the broken line externally.

After reading as many posts as I could on the subject over the course of a few months waiting for all of my parts to arrive and spare time on my hands, I am sitting on the fence about what to do about the brake lines....

They all look like they are in serviceable condition (the metal ones - I have all new rubber ones waiting to be installed this week as well as wheel cylinder rebuild kits). I have replaced my fair share of lines so I know what to look for, but it is a good opportunity to do this while I'm under the truck.

My conundrum is that half the posts say that the old steel lines are twice the strength and durability of the new stuff so leave them until they have to be replaced.... The rest say to yank everything and go with new....

I'd like to hear what you have to say!!!

PS: Later tonight when I get back in from the shop, I'll post a picture of my modified garden sprayer idea that I got from this site. My two fold plan with the garden sprayer is
1. If I leave the old lines (which is where I'm leaning), I'd flush them directly from the brake line that leaves from where the airpack was located. The thought of running denatured alcohol through my freshly overhauled items didn't sit well. IMHO...
2. Use snow plow hydraulic quick disconnects from the garden sprayer to the Master Cylinder remote reservoir - just disconnect the reservoir line and quick connect it to the garden sprayer - minimal air bubble intrusion - flush lines - when finished just disconnect and reconnect. No wrenches required!!!

And tomorrow, after I pick up a few more parts, I'll post my remote brake reservoir Idea pictures...

Thanks and lets keep EM Rollin'!!!

 

[nk14zp]

I would keep the steel lines.If you need a hand I am only 50 or so miles away be glad to help.

 

[DieselBob]

I just went through the rebuild process and chose to keep the original hard lines after inspecting the outside for rust / corrosion.

 

[cityslug]

I would keep the steel lines

 

[gimpyrobb]

Ehh, they might have been twice what we have today 40 YEARS AGO, but prolly not today. If you are replacing everything else, why leave ANY QUESTION about the hard lines, it will not take THAT much more time to swap them out and they are cheap, its just effort. They are alot cheaper than the BFS that will leak out if they fail. Think about how much MORE line pressure you will have once all that gunk is cleaned out from the master and booster. Just my opinion.

 

[clinto]

Hard lines wear out (corrode) from the inside out.

So if they look good on the outside...... well, they may not look so good on the inside.

 

[bratpackdad]

Yep. I found that out the hard way.

 

[RangerDave]

Thanks for the offer nk14zp!!! I got the airpack and Master rebuilt last night after some nit picky cleaning and throwing couple of coats of paint on them... Should be good to go back in the truck after the paint cures for a bit.

I took the liberty of addressing the 1/4 plug problem by replacing it with a close nipple and an end cap - and yes, the darn thing was pretty stuck and it took a bit of heat and PB blaster to get it off without stripping it out...

Also, here's my mod of the spray bottle adapted for purging the lines by bypassing the MC and AirPack... I discovered that the plastic tube was a standard size so I got a flare nut and a compression sleeve and threw in an O-ring for good measure. Now you can tie in strait to the system with the MC and AP removed.

I'll post a couple of pics of my remote reservoir mod as well...

 

[gimpyrobb]

Why would you want the MC & AP removed? If you hook up to the MC, you can bleed everything at once.

 

[Alredneck]

I like the quick disconnect idea! If you have bad luck all the time like me then it would make replacing things that much faster adn less chance of air getting into the system!

As for hard lines! I am like knowing my stuff will function better than the original after replacing parts. Im not a big fan of plastic ( poly whatever it made of ) but at the same time its cheap, easy to fix, can find it just about anywhere. Where hard lines can be harder to find and require special tools to put together properly. Im not a fan of union couplings as quick fixes on hard lines either!

 

[RangerDave]

Ahhh Yes, Thanks for the advise. A little more info I should have included.... Its a 1971 M36 Long Wheel base and never left the road. It was completely overhauled in 1991 - everything - The Master Cylinder was still just primer red. So I'm guessing by the looks of things the system is about that era....

@ MR.Gimpyrobb - The MC and AirPack are removed to be rebuilt. I would be flushing the rest of the lines of any gunk/water with denatured alcohol without having to flush through my rebuilt equip... Unless of course, that is a bad plan.... Your expertise carries a great deal of weight in my book!

Once flushed or replaced and the system is whole, then I'd bleed the system with the modified sprayer...

Here's the picks of my remote reservoir and quick disconnect idea that incorporates the sprayer. Essentially, the small reservoir acts as an indicator of an issue since the main volume is still in the original MC, I'm leaning toward mounting it in the cab. To flush the system, just quick disconnect the line to the reservoir and connect it to the sprayer and bleed the system away. when done, just reconnect it to the tank with minimal air intrusion.... hopefully.... At least this way, it would encourage bleeding the system on a more regular basis!!!

I'm using a couple of snowplow quick disconnects off of one of my parts plows and suck a few hose barbs on them ... we'll see how it works in the next coming week or so when I can get the truck into a garage out back so I can pull all of the wheels to do wheel cylinders, bearings and seals....

 

[gimpyrobb]

My bad, your bypassing the MC & AP to flush the system! I thought you were trying to bypass them to BLEED the system. I'll shut up now.