squirebill Posted October 21, 2016 Report Share Posted October 21, 2016 OK....so I recently rebuilt the brake system on my B1B Dodge truck. This left me with a bunch of non-useable parts. I dissected the three hoses and the one old brake line. This truck was my daily driver in the early '70s and I mothballed it I think '74 or '75. It's been sitting for awhile. So I took pictures of these items and will try to attach them to this post. There is a photo showing the outside of the hard brake line and the degree of rust on the OD. I cut this tube lengthwise for an inch or so to see if it was rusted on the inside. I can't say it looked rusty but it certainly had a black coating on the inside that didn't seem to wipe away but could be scraped off. At this point I tipped the line and was surprised to see that there was still fluid in the line. I dumped the fluid onto a white card and it can clearly be seen that the fluid is contaminated with particles of rust of various sizes. Then cut the three hoses and found they all had different IDs. IDs were .070", .090, and .110 ". Must have been individually replaced at some time and all came from different sources The end of one hose fitting was completely pinched closed so I cut this fitting in half lengthwise and rolled the hose out of one half of the fitting. Looks to me like the inside of this hose fitting rusted and as the layer of rust grew it reduced the ID of the fitting and pinched the hose to the point were it was completely closed off. So what I learned from all this was that although the OD of the hose is about 1/2 inch, the ID is small enough that it could be easily closed off if it got clogged with debris like the rust particles from the hard line. Having the lines rust on the inside even though they are filled with hyd. fluid is possible. The ID of a rusting component can be reduced as the rust layer grows. Also, I once had a '65 Chevelle were the right rear wheel would lock up and skid when the brake was applied. Checked the brake on the right rear and all looked good. Pulled the left rear brake and found the friction material was contaminated with oil from a leaking axle seal. Recommend you check your other brakes for contamination as the right front brake may be trying to compensate for other non-effective brakes. Also, my daughter had a '87 escort where the left front wheel would lock up after the car had been driven for a while and making multiple stops during the trip. This was a disc brake situation. Traced it down to the brake hose going to this brake. It had a 1 inch wide steel clamp that wrapped completely around the hose at about mid length and held the hose to a bracket on the front strut. This clamp had rusted to the point where it choked off the hose ID. The thinking was that pedal pressure could go to the brake but once pedal pressure was released pressure would not be released properly because the hose was constricted. Maybe some of this will help you diagnos your situation. Regards Attachments (43).zip 3 Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 21, 2016 Report Share Posted October 21, 2016 Great pictures...thank you for posting! Good for everyone to see these. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 21, 2016 Report Share Posted October 21, 2016 SquireBill; Thanks for putting the visual aids to this. That is exactly what I was trying to describe in my posts #16 & #23. Internal corrosion like this is pretty insidious stuff.......... stays hidden until it finally bites you. If you think that 60 year old steel lines don't have some of this going on it is just wishful thinking. I would urge anyone working on one of these old vehicles to pay heed to this. Jeff Quote Link to comment Share on other sites More sharing options...
ggdad1951 Posted October 21, 2016 Report Share Posted October 21, 2016 this is why I did the cupronickle lines on FEF...will never corrode! 1 Quote Link to comment Share on other sites More sharing options...
squirebill Posted October 22, 2016 Report Share Posted October 22, 2016 Thanks everyone for the kind comments. Good to learn things from simple efforts. What really surprised me was when I cut the hoses. I was surprised at how small the ID was. The largest was only .110 inches ID. Having seen the 1/2" OD I was guessing the ID would be something like 1/4" or even 3/8", something like a fuel line hose. Now in the past I had heard of brake lines "ballooning" but now having seen these IDs I wonder how much ballooning could occur. I cut my hoses up so I can't test this. But if we take the largest hose ID (.110 in.)I had and figure the volume for an 18 inch long hose we get 0.685 cubic inches. If the hose ballooned to twice it's original volume, it would be 1.37 cubic inches. This is a considerable volume for this brake system and when you figure there are 3 such hoses, that comes up to a little over 2 cubic inches of fluid to cause the ballooning. This 2 cubic inches coming from the master cylinder that has a reservoir volume of 11.5 cubic inches could require the brakes to be pumped in order to come to a stop. Anybody have any thoughts on this. 1 Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 24, 2016 Report Share Posted October 24, 2016 Consider the psi that can be in the system when a 200-250 pound person stands on the brakes in an emergency factoring the 6 or 7 to 1 ratio gained by the leverage of the pivot point of the pedal and application point of the push rod and you can easily get into the 1500 psi range internally. Anyplace the system has a step down in diameter like the fittings at hose ends or makes a turn can be a collection point for debris. Quote Link to comment Share on other sites More sharing options...
PT81Jan Posted October 24, 2016 Report Share Posted October 24, 2016 (edited) Remembers me to a brake issue that I had some years ago on my motorcyle: Used a DOT 5 brake fluid which (slowly) lead to swelling rubber parts inside the brake cylinder. The pressure was high enough to move the piston out but it didn`t move back in the proper way. Became aware that I should have used DOT4. (Some men are trying out before reading ...). Did you use an other brake fluid when changing the cylinders ? Just an other thought, Jan Edited October 24, 2016 by PT81Jan Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 24, 2016 Report Share Posted October 24, 2016 ^^^^^ Mixing by accident DOT 5 silicone and DOT 3 or 4 polyethylene glycol based brake fluids is a bad thing to do! The whole brake system must be 100% flushed out with alcohol or brake cleaner and blown completely air dry if switching fluid types and if contaminated ALL rubber parts have to be replaced. Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted January 3, 2017 Author Report Share Posted January 3, 2017 I know it has been a while, since October to be exact, but I finally got the flex brake lines replaced this last weekend and so far the brakes work well. I am cautiously optimistic, because they worked well for a while after I replaced the front cylinders too, and then the right front started locking up again. I will drive DD more next weekend and find out whether the flex lines replacement is the solution or not. Sure is nice not to have the right front locking up, I hope it is fixed. The attached photo was DD's last run to the dump in August. I have the heater all hooked up and the fan works. I got the defroster ducking in, and now all I need to do is hook up the heater to the hot water and the old girl will be good to go!. 1 Quote Link to comment Share on other sites More sharing options...
Reg Evans Posted January 3, 2017 Report Share Posted January 3, 2017 Hey, mighty nice looking hub caps you've got there ! 1 Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted January 3, 2017 Author Report Share Posted January 3, 2017 DD is very happy with her new hub caps!!! Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted January 16, 2017 Author Report Share Posted January 16, 2017 So far the flex line replacement seems to be working. Brakes are working great. Dd went to town for some lumber today.. Gorgeous day. 1 Quote Link to comment Share on other sites More sharing options...
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