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06-19-2003, 09:56 PM | #1 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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Stupid brakes
I was checking fluids on my truck the other day, and i notcied my brake fluid was a bit low in the rear resivour. No big deal, so i filled it up. Today i went to stop the truck, and i felt the brake pedal sink underneath my foot more than nomral, so i checked it again, and sure enough, it was low. I started looking and found that the brake line for my rear brakes, the one that crosses the front suspension X-member, had worn a hole in where it meets the frame. No big deal, so i took out the old line, and went to the parts store and got a universial bend-to-fit replacement. I put it in with no problem, and went to bleed them with my mity-vac bleeder.
Anyway, i was just pumping air and no brake fluid, and the level in the MC wasn't dropping, so i got in the truck and stood on the brake pedal to check for a leak. Sure enough, the brake fitting was leaking where the lines join going from the mastercylinder and the one that goes across the X-member. The fitting on the new line is the same thread as the old line, and it seems to be leaking where the line goes into the fitting that slides up and down the new brake line. I was thinking of just replacing the union for the two brake hoses and seeing how it works then, but that is just a guess. It didn't leak before and it looks fine. Any other ideas on what would make it leak like that?
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
06-19-2003, 10:06 PM | #2 | |
Bloo
Join Date: Feb 2001
Location: Barren County Kentucky
Posts: 6,283
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i gotta ask, did you flare it before putting on the fitting?
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ASE Master Certified-GM Trained-Mechanic 1968 Chevy C30 157" WB Wrecker 1969 Chevy CST/10 SWB 1971 Chevy Custom/10 (first truck) 350, NV3500 5 speed 1971 Chevy K20 Custom Camper 4x4 350 TBI, SM465/NP205 1974 Chevy Custom Deluxe/10 1979 Chevy Custom Deluxe K10 farm truck beater 1989 Chevy K2500 Quote:
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06-19-2003, 10:11 PM | #3 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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Yup, the line was pre-flared with the fittings on it.
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
06-20-2003, 02:17 AM | #4 |
Registered User
Join Date: Dec 2002
Location: Central California
Posts: 88
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brakes
I hate to ask this but I ran into it. The replacement line isn't metric by any chance is it? Just enough smaller to leak but not enough to be detected????
Just a thought
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Greg72 |
06-20-2003, 09:30 AM | #5 |
Senior Member
Join Date: Jul 2001
Location: Muskegon,MI,USA
Posts: 6,026
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Sometimes you have to tighten the fittings a lot to make the old and new flares seat.
Jim |
06-20-2003, 09:59 AM | #6 |
Fabricate till you "puke"
Join Date: Jun 2002
Location: Ill
Posts: 9,402
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another thing to look at, is that the flared end of the new line is smooth......I have seen new lines with a small crack in the fold on the double flare. Also I have seen a small pc of rust or dirt get between the line & its seat, causing a scar.....some of that stuff will make you "nuts"! I would try tightening the line more, as Jim has suggested tho..... good luck,crazyL
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69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears.... |
06-20-2003, 11:35 AM | #7 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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Well, i torqued down the lines until the end on my cheap flare wrench spread apart, and that seemed to solve the problem. I wrapped some paper towles around the fittings at both ends of the line, got in the truck, and pumped up the brakes. Both towels were dry, so that solved the leak problem.
However, i am having problems bleeding the brakes. I am using a Mity-Vac pump, which seems to work good so far. I will pump it up, open the bleeder valve at the wheel cylinder, and i have been getting LOTS of bubbles in the system. I have filled up the container with about 2" of brake fluid 2 times, put the fluid back in the MC, and now the pump is drawing just air and no fluid at all.....and the level in the MC isn't dropping at all. I haven't found any other leaks in the brake system, and i have the fitting for the pump on right (the vaccum guage shows no drop in vaccum when i hook it up with the bleeder valve closed). Also, if i go pump up the brakes after i get nothing but air out of the bleeder fittings, i will then get a mixture of air and fluid (mostly air though) Brakes have never been my strong point. What am i doing wrong here?
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
06-20-2003, 11:36 AM | #8 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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Also...
I have been bleeding with both the MC cap on and the MC cap off, and it dosen't seem to make any kind of a difference.
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
06-20-2003, 12:11 PM | #9 |
Registered User
Join Date: Oct 2002
Location: Des Moines WA. (Kent, area)
Posts: 668
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Try bleeding the M/C the oldfashioned way then when done rebleed the system.
You probably got air in the M/C
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06-20-2003, 12:12 PM | #10 |
Senior Member
Join Date: Jul 2001
Location: Muskegon,MI,USA
Posts: 6,026
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I think that you have Murphy helping you!
Rear brakes can be a real problem to bleed sometimes. I am wondering if your prop valve has not shifted. I would try bleeding the master cylinder and the prop valve by removing the line from the rear of the prop valve. Once your fluid flow is good through there go back to the rear and try again. Good luck it will only take two more days to get it bled! (Just half kidding!). Jim |
06-20-2003, 01:29 PM | #11 |
Formerly yellow72custom
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
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Woo Hoo! They finally work again.
I bled them the old fashioned way, using my sister to press the brake pedal, and i layed down by the bleeder valves using a bottle of brake fluid and a clear hose. Took like 5 minutes and the brakes work great. This is acutally my first successful brake job, lol. Now, one more question. The replacement brake line dosen't have the wire shield wrapped around it like the original did. I can't put the old one back on, so i bought some 3/8" fuel hose to wrap around the line where it comes close to the frame. Think this will keep a hole from being worn in the brake line again?
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'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg |
06-20-2003, 01:42 PM | #12 |
Resident Curmudgeon
Join Date: Dec 1999
Location: NH
Posts: 6,662
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That wire wrap is on the OE lines only to allow them to be factory pre-bent without kinking the brake lines. It's not there to protect the lines after install though I suppose it would to some degree.
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Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all |
06-20-2003, 01:47 PM | #13 |
Senior Member
Join Date: Jul 2001
Location: Muskegon,MI,USA
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The springs are put on to protect from stones and debris damage.
I think what you did will proect it from wearing through. It is a little unsual to have a line wear through as they are usually held securely against the frame. Good job! Jim |
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