The Stovebolt Site Forums The Shop Area General Truck Talk "Why'd they do it that way? " - '89 Chevy 2500

Started wrenching on my '89 Chevy 2500 truck last week...this is the newest Bow-tie I've ever touched, so please pardon my "ingorance"...

WHO at GM came up with the brilliant idea to put 9/16" hex flare-nuts on 3/16" brake-line tubing ???? :mad:

Not only did the flare-nut wrench begin to round the corners on the 9/16" nut-heads, but 2 out of 3 wrung the hex off, leaving the threaded stub (and line) tightly buried in the wheel-cylinders and brake hose.

While this is certainly not my first experience with crusty brake plumbing, this is the first time I've run into these B-A flare nuts, and I don't think I like them !

I needed to replace the lines on the rear axle and the rear WC's any way, so it's not the end of the world...but I will be putting back lines with regular-sized 7/16" hex flare nuts...

Thank goodness the fitting from the main line into the rear brake-hose came loose...

Once again, I'm a victim of "Progress" !
:p

Frank,

I'm innocent. I always use vise-grips to bust the fittings loose, then you can use a flare nut wrench. My experience has been a flare nut wrench will not break a tight nut loose..only round it over. I was hung-drawn-and quartered for my opinion on this subject, but I'm sticking to my guns.

Remember as you work on the newer rigs, all engineering decisions are based on $$$. Somehow, it was more cost effective for GM to use that size flare nut.

Stuart

atomarc is got it right.. it's all about saving a nickle.. or even a half a penny sometimes.

Dosen't sound like much difference, a half a cent.. but when you multiply that by a dozen or so then multiply that by the millions of vehicles they sell, it adds up.

My first experiences with wrenching on cars were the late 70's models.. and I found the newer they got the more confusing and just in general pains in the [censored] they were.. makes me appreciate working on my 60 year old trucks all the more.

A proper wrench and a GOOD wrench help a lot. Since it's an '89, it could have been a metric nut. A flare nut wrench should fit extremely snugly. Cheaper brand wrenches usually don't.

I don't know...my HF flare wrenches fit very snugly around flare nuts. On older stuff, I always just used a pair of vice grips and start replacing lines.

i had a 92 and ran into the same problem. i replaced the lines with some braided stainless lines. i ended up re-engineering so much crap on that thing that i got rid of it because i hated working on it, i think that made them hard to work on on purpose. that way i have to take it to the dealership. i sold that bucket down the road and bought my '61, which i could take completely apart with a socket set, some wrenches and a pair of screwdrivers. of course my 61 has those dumb clutch head screws but that is my only pet peeve thusfar and they aren't really that big of a deal once you buy the clutch drivers. anyway my advice is to get ready to run into a lot of backwards engineering. it was what ultimately made me get rid of mine. i liked it but i could not work on it effectively. i have run into the same situation with many new vehicles, which just reinforces my love of old and easy to to work on vehicles.

want a GREAT flare nut wrench? Cornwell makes a set of 3/8" crowfoot flarenut wrenches that are the bomb! I used them for years in the garage where I worked,and they're beefy enough that they just don't flex. I was amazed at how well they worked,and I tried Snap On,Craftsman,Proto,S-K,but so far,Cornwell beats 'em all. (haven't tried MAC yet,my bro says they're good too.) One trick is making sure you get a good straight pull on the wrench;if the wrench tips at all from straight,it'll slip. Get your wrench aligned and hold a little pressure on it to keep it located,then give it a smack with your othewr hand to overcome the "sticktion" that keeps the nut tight. It should pop loose.I'd also used a small C-clamp on the jaws of the wrench to keep them from spreading and slipping on the nut,before the "good" wrenches.
Speed