Master cylinder brake lines broken

[circleD]

Has anyone ever broken the brake lines on aaster cylinder while taking them off for a MC replacement? I'm just curious because the shop broke mine and ordered new lines to replace them. I hope it's the entire line to the block and not a fitting  D:oH!

[legomybago]

Sounds like some rusty brake lines or a rookie move...better check all the brake lines out. Did the system set empty of fluid for a length of time? Why did you need a new MC? Doesnt surprise me that a mechanic broke something...They were probably pis*ed off trying to get the lines broke free up underneath the rig...

[circleD]

The MC was leaking and it sat for a few days low on fluid until I filled it up to take it for repairs. I sprayed the mounting bolts and the lines everyday for 4 days prior. I just hope they don't cut out the line near there and try to make a double flare and patch it. I was just curious if any of you diy'ers have had issues like this. The guy did chuckle when he said there was a good amount of rust under there. Access to the MC was open and with the doghouse off you could reach the brake lines. IDK of they did that though.

[M & J]

Golly D. I had no problems at all breaking my flare lines free. One squirt with penetrant and even working from the blind side they came right out.

GM says the OEM lines are no longer available for a very long time and any place that lists them is selling 25' of tubing and 2 connectors.
Be aware, the combination valve is unobtainium so hope they get those flares loosened.

Also, if done properly, a double flare splice is ok to have. Having just gone through having to rebend a replacement line, I'd much rather have made a short section with only a bend or two and a splice than having to duplicate the factory original end to end then worm it back in place.

[Rickf1985]

I would cut that line off flush at the fitting on the combo valve and then use a 6 point socket to remove the fitting. The line is broken, why even ply with a line wrench now? The just make up a new line. And as was said, this is the perfect time to check the rest of the lines since you are out of fluid and have to do a complete bleed anyway. That will give you new master and new lines and fresh fluid in the whole system.

[circleD]

I was about to ask the question about splicing a new piece in with a flared end hooked to the MC and run a piece of metal line to a good solid spot on the original line and use flared union. Will that patch hold up to 15,000 pounds of RV reliably? Or do I need to make sure there's a one piece line reinstalled?

[M & J]

I think a spliced line will be fine as long as they cut in to good solid line to double flair. Lets see what Rick or others have to say though. I've seem many factory lines spliced to make installation and assembly easier right from the factory.

[Rickf1985]

The union is fine as long as it is a brake line union and not a compression fitting. Those line unions are used in manufacture to extend the lines of vehicles that have frames stretched. On a short run like that though and considering the age of the line I would personally replace the whole line. That is just the mechanic in me talking, do it now or do it down the road a bit when the other half rots out.

[circleD]

The MC is fixed with 2 new lines. Here's some pics of the old one and the lines that broke. All I heard was how rusty everything is under there and I replied with "yes I'm aware of the rust" but a good mechanic will know what to do. On the new lines one of them is a double flare connection and the other is a new piece. The brakes are a little better with some travel before stopping power is applied that I can really feel. I know this thing isn't a corvette and want leave skid marks.

[Rickf1985]

That one sure looks like a piece of copper tubing! I hope that is the one that was replaced!!!

[circleD]

Between the rust and dirt it has a copper look. It's factory so I hope not. The pedal still goes halfway until they start to slow it down though. I'll do some research later through posts.

[Rickf1985]

Sounds like you have air in the system. A complete bleed is in order.

[circleD]

They bled the system and I hate to redo it. But yes I agree that is the main issue. I'll try to narrow it down and post way later.

[Rickf1985]

How much free play is there in the pedal?

[circleD]

The first 1/4 of push is easy with slight resistance then when it gets 1/2 way its kinda firm and by 3/4 its hard. IF I pump the peddle a few times it gets firm by the first 1/4 of travel. I'm going to double check my wheel cylinders for fluid slinging out and disconnect the TAG axle part since it slowly drips. I hope the TAG part hasn't caused any air to get in.

[legomybago]

If you have a leak anywhere in that system, your sucking air. Damn brakes

[Rickf1985]

The first 1/4 of push is easy with slight resistance then when it gets 1/2 way its kinda firm and by 3/4 its hard. IF I pump the peddle a few times it gets firm by the first 1/4 of travel. I'm going to double check my wheel cylinders for fluid slinging out and disconnect the TAG axle part since it slowly drips. I hope the TAG part hasn't caused any air to get in.

That sounds like you have drum brakes and the shoes are out of adjustment. Is your emergency brake on your rear wheels or on your driveshaft? If it is on the wheels it also has to be adjusted correctly, if it isn't you will never get a good pedal.

[pvoth1111]

Brake lines are steel....never copper....

[circleD]

I have rear disc and the e brake is behind the transmission. I tried to disconnect the TAG but i didn't want to destroy parts that I might need later.

[Rickf1985]

Well that is narrowing it down. Do you have any pulsating in the brake pedal when stopping, like a vibration you can feel with your foot? That would indicate a warped rotor and that could cause the caliper pistons to be pushed back while driving which would give you the low pedal at first push. Another thing that can do it is loose wheel bearings. I am still thinking air in the lines but those are other things to check.

[circleD]

No pulsating and even though they "BLED" the lines I'll probably rebled them after I disconnect the TAG. I'm trying to keep this in relation to the brake lines being old and seized "broken" at the MC due to post title. I haven't made a test drive with the freshly cleaned tires on the inside due to weather. That'll help determine a wheel cylinder or something. Those guys didn't use a hose to catch the brake fluid and it made a mess.

[Rickf1985]

If you are going to bleed the brakes you have to do it right. Longest run first which would be the right rear tag, then left tag, right drive, left drive, right front, left front. Dirty contaminated fluid will give a spongy pedal also but I don't think that is your problem here especially if it were only the tag. That does not mean that air could not have worked it's way into the lines going to the tag axle so they all have to be done. I have found that a vacuum bleeder to have the best results. A pressure bleeder, if used incorrectly, can fill the system with foamy fluid and that will cause all kinds of problems, including what you are experiencing right now.

[DaveVA78Chieftain]

Tag is normally a separate system.  Have you read this? http://www.classicwinnebagos.com/forum/index.php/topic,9132.msg46674.html#msg46674

The hydroboost system is discussed here: http://www.classicwinnebagos.com/forum/index.php/topic,9126.msg46599.html#msg46599


Dave

[HandyDan]

Thanks Dave, I was going to post the same thing.  The tag axle has its own master cylinder and doesn't use any brake fluid from the main master cylinder.

[circleD]

That's why I take the rear tires off because the tag axle prevents me from getting a good position. My tag brake system is shot.