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MGB-GT MGBGT brake part replacement questions

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davester

davester

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I'm busily replacing the brake system in my 71 BGT and have run up a couple of issues:

1. The new wheel cylinders I bought (about 7 years ago, so no returns) have turned out to be roadster cylinders. That is, they have the locating pin in a slightly different position. The parts house suggested that I just redrill the back plate to take the roadster pin and indicated that the small difference in piston size for roadster vs GT won't make much difference. I'm tending to agree with this, since I haven't really had any back brakes for quite some time, seeing as the brake lines turned out to have been squashed (owing to a flatbed ride and sloppy operator tie down job since about 15 years ago. Any pitfalls with this approach?

2. The new front flexible brake lines are only 14" long (compared to the 15 3/4" long never before changed originals). This results in the brake line being pulled fairly taut with the wheels at full lock. I've checked a few sources and all of the new brake lines available seem to be only available in 14" length. Has anyone had any issues with this?

3. The original flexi lines have a coiled spring wire surrounding the flexible line. I'm assuming that this is to prevent chafing against suspension parts. It doesn't look to be easily transferable to the new flexi lines. Do most people just run the flexi lines without the wires?

Thanks for any advice!
 
Hiya Dave! Welcome to th' fracas!

1: Locate those holes well. The GT would actually be better off with the proper cylinders though, IMO. Going to GT cylinders in a roadster would be the better way. They're not that expensive, actually.

2: Do you have a good hydraulics shop nearby? AeroQuipt lines made to order would be my suggestion.

3: Braided stainless wouldn't need extra protection.

It's brakes we're talkin' here... run it all day without gas but don't even START it without BRAKES!

...what value do you place on your butt... /bcforum/images/%%GRAEMLIN_URL%%/jester.gif
 
Welcome to the BCF and what he said /bcforum/images/%%GRAEMLIN_URL%%/smile.gif
 
what Doc said.

However, when I replaced the flex lines in my roadster the new lines came with the coil wrapped around the flex line. So, there was no need to recycle the old ones.

Like you, I've noticed that the new lines are slightly shorter than the old lines. Fortunate for me, the line isn't the limiting factor when I turn to lock, but they do come ~very~ close to being taut.

I've noticed that the rubber hydraulic lines that I get from the 'major suppliers' these days don't seem to last very long (2 rubber clutch flex lines in as many years). I plan to switch to stainless braided lines within the next year or so.
 
Have 'em "made to order" locally by a hydraulics shop, Rob. I dunno if I'd expect any of the mail-order ones to last any longer than the "standard" variety.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]1. The new wheel cylinders I bought (about 7 years ago, so no returns) have turned out to be roadster cylinders. That is, they have the locating pin in a slightly different position. The parts house suggested that I just redrill the back plate to take the roadster pin and indicated that the small difference in piston size for roadster vs GT won't make much difference. I'm tending to agree with this, since I haven't really had any back brakes for quite some time, seeing as the brake lines turned out to have been squashed (owing to a flatbed ride and sloppy operator tie down job since about 15 years ago. Any pitfalls with this approach?[/QUOTE]

Not only "locate 'em well" but be prepared when you end up with 1 elongated hole! The 2 holes are so close to one another that, if you're off just a little, they become 1!

I would get the correct cylinders! You can always sell the incorrrect ones.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]2. The new front flexible brake lines are only 14" long (compared to the 15 3/4" long never before changed originals). This results in the brake line being pulled fairly taut with the wheels at full lock. I've checked a few sources and all of the new brake lines available seem to be only available in 15" length. Has anyone had any issues with this?[/QUOTE]

You'll pop those hoses within a month if you ever go 'lock-to-lock'....the OE & aftermarket ones from Moss are the correct length...they're the ones you need. I just installed a` set I got from Moss & tey're the correct length (within tolerance)

But, a question: where are you hooking them to the caliper? Top hole or bottom hole?


<div class="ubbcode-block"><div class="ubbcode-header">Quote:]3. The original flexi lines have a coiled spring wire surrounding the flexible line. I'm assuming that this is to prevent chafing against suspension parts. It doesn't look to be easily transferable to the new flexi lines. Do most people just run the flexi lines without the wires?[/QUOTE]

Yep, not needed with the braided lines - only the rubber ones.
 
The stainless hoses from Moss (as of a few months ago) are too short. They won't break off, but they do pull tight at lock. I've been running them on two cars but do plan to change them out before long. If you order these hoses, be sure to check the length when you take delivery.
 
Just my $.02 on the wheel cylinders. I would get the ones that the car requires. They have a smaller bore and thus provide more pressure to the shoes. This is to compensate for the added weight of the GT. That and you won't have to drill your backing plates.
 
I suppose you guys are right and I should get the proper cylinders (though I just noticed that the OEMs from Moss cost twice as much as the roadster cylinders...are the [cheaper] aftermarket cylinders any good?). I was all set to get the car back together this weekend but I guess I'll be waiting on parts...AGAIN!

Another peripheral issue. The flexlines didn't come with replacements for the copper washers where the lines screw into the calipers. Is there any issue with reusing the old washers?
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]are the [cheaper] aftermarket cylinders any good?). [/QUOTE]

They're the only ones I use...just put 2 on my '74-1/2 GT.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]The flexlines didn't come with replacements for the copper washers [/QUOTE]

Mine did - what brand are yours?
 
After market cylinders are fine, although I don't feel they are the same quality as Lockheed OEM parts. The only brake caliper I've ever had fail was and after market one.

New lines should come with washers, but you can use the old ones if they are in good order. If they don't leak then they are fine.
 
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