Brake line/fittings sizes.... - Second Generation Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Brake line/fittings sizes....
Thursday, December 13, 2012 6:05 AM
I have a 1989 Chevy Cavalier base coupe that developed a brake leak. A quick inspection showed that the RR brake line is rotted, with the leak visible at the metal brake line fitting, where it joins with the front end of the hose at that wheel.

The car is remote right now, I do not have access to it. Does anyone know off-hand what the thread sizes are for the fittings that go into the master cylinder for this car? I want to disconnect the line(s) at that point and quickly install a bolt or plug, to prevent leakage and to keep air from entering the wider system. Off the top of my head, I am thinking an M12 thread?

Re: Brake line/fittings sizes....
Thursday, December 13, 2012 7:05 AM
From what I remember redoing all of mine, they are not a fitting you can redily get as I had to run a conversion adapter on mine.



Re: Brake line/fittings sizes....
Thursday, December 13, 2012 9:10 AM
jason norwood wrote:

From what I remember redoing all of mine, they are not a fitting you can redily get as I had to run a conversion adapter on mine.

Yes, I remember this from when I went to replace a front brake line on this car a year or two ago. Between the MC fitting being odd and the difficulty in routing the brake line cleanly from the MC to the caliper (and this was just to the LF wheel!), I decided to flare the existing brake line near the caliper, and then use a union and finish the line to the caliper.

But the point is... I am not looking to use a brake line fitting at the MC, just a bolt to temporarily screw in to hold the fluid while I work on the brake line. I do not want to have to bleed the entire system.

Thanks.
Re: Brake line/fittings sizes....
Friday, December 14, 2012 4:52 PM
Which MC is it? ABS or non?

.



Re: Brake line/fittings sizes....
Friday, December 14, 2012 8:03 PM
Just by a vacuum brake bleeder from harbor freight. They. have one that hooks up to the air compressor for $20. They also have a hand pump one you connect to the master cylinder that pumps fluid through the lines for $20. You can bleed all the lines in less then 10 mins Also the non abs master cylinder takes two large green fittings and two small gold ones I believe. That is if you get them from advanced auto. I just redid all my lines for $100.




On the inside my car looks like a fighter jet.
Re: Brake line/fittings sizes....
Saturday, December 15, 2012 5:45 AM
James Cahill wrote:

Which MC is it? ABS or non? .

Non-ABS.
Re: Brake line/fittings sizes....
Saturday, December 15, 2012 6:01 AM
Rob Dotterer wrote:

Just by a vacuum brake bleeder from harbor freight. They. have one that hooks up to the air compressor for $20.

Air Compressor? .

Rob Dotterer wrote:

They also have a hand pump one you connect to the master cylinder that pumps fluid through the lines for $20. You can bleed all the lines in less then 10 mins

IIRC, you will have to bleed all of the lines and the MC if the MC runs low. Not a problem in the shop, but a pain on the driveway with minimal tools. I am aiming to only having to bleed one or both rear lines.

These aren't tools I will use too often.

Rob Dotterer wrote:

Also the non abs master cylinder takes two large green fittings and two small gold ones I believe. That is if you get them from advanced auto..

I have no idea what this means. From what I recall, there are the 4 fittings at the MC, and I don't think they are all the same size. Again, I am remote from the car right now, but I should look at it today.

Rob Dotterer wrote:

I just redid all my lines for $100.

I am not spending anywhere near $100 for this job. I am lazy AND cheap.
Re: Brake line/fittings sizes....
Sunday, December 16, 2012 9:51 PM
If you go to advanced auto, they have a section with brake line fittings, I may be able to take a picture for you but they come in colors, they have two green ones a small one and a large one, the same with gold. That is the only way I can describe it for you without knowing the size. You can also just by them and return the ones you do not need.




On the inside my car looks like a fighter jet.
Re: Brake line/fittings sizes....
Sunday, December 16, 2012 10:10 PM
Rob Dotterer wrote:

If you go to advanced auto, they have a section with brake line fittings, I may be able to take a picture for you but they come in colors, they have two green ones a small one and a large one, the same with gold. That is the only way I can describe it for you without knowing the size. You can also just by them and return the ones you do not need.

Thanks for the offer, but no need to take a picture, I understand what you are saying now. I might be able to deduce the fitting sizes from this. Project is on hold until later this week.
Re: Brake line/fittings sizes....
Monday, December 17, 2012 3:48 PM
I just dug through all my info. I was only able to confirm the ABS MC sizes, but something rings in my memory that the rear lines are 12mm and the front are 10mm. They're a strange pitch though and IIRC you aren't going to find a bolt that will thread in. I went through all sorts of trouble finding a fitting that worked when I swapped to the N body MC (which had the same fitting size) and I needed to convert it to -3AN. It's a bubble flare (not compatible with a 1/2 inverted flare, even though some people think it is), which is impossible to make without a hydraulic flare tool. My suggestion if you can't find something at Autozone- buy an entire MC. They typically come with plastic plugs in the ports (some are simple push in, others are threaded, just make sure you get a threaded one). Use the plug on yours, then return the MC.

.



Re: Brake line/fittings sizes....
Monday, December 17, 2012 4:23 PM
James Cahill wrote:

I just dug through all my info. I was only able to confirm the ABS MC sizes, but something rings in my memory that the rear lines are 12mm and the front are 10mm. They're a strange pitch though and IIRC you aren't going to find a bolt that will thread in. I went through all sorts of trouble finding a fitting that worked when I swapped to the N body MC (which had the same fitting size) and I needed to convert it to -3AN.

It's appreciated, but you went through way too much work, unless it was to satisfy your own curiosity.

As I mentioned above, I also remember an odd fitting when I went to attach a brake line a year or two ago. That is why I asked if anyone knew what the threading was offhand.

James Cahill wrote:

It's a bubble flare (not compatible with a 1/2 inverted flare, even though some people think it is), which is impossible to make without a hydraulic flare tool.

I believe I have done a "double flare" on the brake lines on this car previously. I have picked up a standard flaring kit as a rental from the store.

James Cahill wrote:

My suggestion if you can't find something at Autozone- buy an entire MC. They typically come with plastic plugs in the ports (some are simple push in, others are threaded, just make sure you get a threaded one). Use the plug on yours, then return the MC..

I didn't think of this... maybe they SELL the plugs or something similar (MC bleeding kit?). I don't like messing with their inventory. And I doubt that I would get my choice of "push" or "threaded" plugs for the MC.

I will figure something out, or I might just have to bleed the entire system. Annoying, but not the end of the world.

Thanks!

Re: Brake line/fittings sizes....
Wednesday, December 19, 2012 12:04 PM
baron5867 wrote:

James Cahill wrote:

I just dug through all my info. I was only able to confirm the ABS MC sizes, but something rings in my memory that the rear lines are 12mm and the front are 10mm. They're a strange pitch though and IIRC you aren't going to find a bolt that will thread in. I went through all sorts of trouble finding a fitting that worked when I swapped to the N body MC (which had the same fitting size) and I needed to convert it to -3AN.

It's appreciated, but you went through way too much work, unless it was to satisfy your own curiosity.

As I mentioned above, I also remember an odd fitting when I went to attach a brake line a year or two ago. That is why I asked if anyone knew what the threading was offhand.


Doesn't bother me. It took under 10 mins and it's nice to know for future reference. I have tons of reference material all in one spot.

baron5867 wrote:

James Cahill wrote:

It's a bubble flare (not compatible with a 1/2 inverted flare, even though some people think it is), which is impossible to make without a hydraulic flare tool.

I believe I have done a "double flare" on the brake lines on this car previously. I have picked up a standard flaring kit as a rental from the store.


It's just that one fitting that's a bubble flare. Everything else is IF (inverted flare, same thing a a double). I've seen people try to use a 1/2 IF in a bubble fitting and it leaks similar to how an IF leaks in an -AN fitting and vice versa. The angle is just a touch off.

.



Re: Brake line/fittings sizes....
Saturday, December 22, 2012 2:09 PM
James Cahill wrote:

It's just that one fitting that's a bubble flare. Everything else is IF (inverted flare, same thing a a double). I've seen people try to use a 1/2 IF in a bubble fitting and it leaks similar to how an IF leaks in an -AN fitting and vice versa. The angle is just a touch off..

Not sure how similar it is, but this past summer, I did use 1/2 of a double flare in place of an ISO metric flare on another car. It did work, and to my knowledge, there have been no problems since then.

(Yep, that is right, this is the second time in 5 months on two different cars that I had a rotted brake line to the RR wheel fail on me in traffic. )

I hope to at least start this soon, the weather is not going to get any nicer. Is there any tricks to getting these brake lines unscrewed, other than loads of PB Blaster? Getting them unscrewed at the rear hoses may be easier, because you can always hold the brake line still and rotate the hose fitting. Thanks.
Re: Brake line/fittings sizes....
Thursday, January 17, 2013 5:33 PM
baron5867 wrote:

Not sure how similar it is, but this past summer, I did use 1/2 of a double flare in place of an ISO metric flare on another car. It did work, and to my knowledge, there have been no problems since then.

Brake lines are 3/16" with ISO Bubble Flares, and 10 x 1.0 mm fittings. AGS is who supplies all of the FLAPS in my area. You want to get their PVF European Steel Line..

I once again used a standard double flare kit loaned from the FLAPS, and only did the first part of the double flare. I picked up a loaner OEM 27015 kit from AutoZone, but I did not like the wing nuts on the clamping bar and the T-handle on the pressing tool. I then picked up a loaner Powerbuit 648610 from Advance Auto, which has has 1/2" heads on the clamping bar and the press tool, and these are MUCH better to work with.

Always check loaner tools before you use them, or even leave the store with them. On flaring tools, make sure that the appropriate hole on the clamping bar (3/16" in this case) has clean sharp threads on it that will grip the brake line when you tighten down on it. Make sure nothing is broken. In my case, I got home and discovered that the Powerbuilt tool I picked up had two 3/16 nipples in the kit instead of one each of 3/16" and 1/4". After a couple of bad flares, I realized that BOTH of the 3/16" nipples in the Powerbuilt kit were bent. I used the 3/16 nipple from the OEM kit to get my flares.

When you use the Poly Armour lines, make sure to strip the plastic coating off the end of the brake line before you put it into the clamping tool, otherwise the clamping tool will bite into the plastic and the brake line will slide out as you tighten the press.

Some people on the internet call for use of the flat side of the clamping tool for a bubble flare with a double flare kit, but I did not like this, and use the normal, beveled side of the clamping tool. The rear side of the flare is going to be conformed to the nut when the line is installed and the brake nut is tightened. As per the instructions, set the brake line to protrude just a hair above the first step of the nipple, then grease the nipple with brake fluid, insert it in the brake line, make sure it is straight, and then tightened completely down with the press tool. Many on the internet make a big deal about prepping the brake line after cutting it, but from what I see, it is just important that the brake line end is parallel with the clamping bar, and the line cutter should take of that.

Although I originally just had a leak on the RR brake line and saw that the RL brake line had already been replaced, I took a closer look and realized that whatever mechanic did that work really did a total crap job. Instead of properly replacing the line and routing it correctly through the support harnesses, the mechanic ran the line under the car, and supported this brake line , under tension, with.... wait for it....a plastic cable tie. Of course, the cable tie had broken (probably several weeks after installation), the line had dropped an inch or so, which put it in contact with the brake hose, and worn about 1/3 of the way through the hose. If this car had normal 12k miles per year use instead of 2k (max) per year, that brake hose would have went a long time ago. Let me rant here... I had to re-do this work the right way (and it is a PITA), because some "professional", who has a lift, better tools, much more experience, and was PAID for the job, decided to do a total hack job, on a brake system. And people wonder why I like to do my own work........

Of, as it is now, the lines are installed and I have bled the two rear lines that were worked. The pedal is still very soft. I am assuming that I need to bleed the entire system, starting with the master cylinder.
Re: Brake line/fittings sizes....
Monday, January 21, 2013 6:11 PM
You're the first person I've seen (short of an actual shop) to actually re-flare bubbles. I'm bookmarking this for future reference.

.



Re: Brake line/fittings sizes....
Tuesday, January 22, 2013 1:44 AM
James Cahill wrote:

You're the first person I've seen (short of an actual shop) to actually re-flare bubbles. I'm bookmarking this for future reference..


(???) You need to get out more. There is plenty of other information out there on this. On youtube alone, there are several videos.

I hope I provided some useful info here, but what I did here is not the proper way to do this repair. It works, particularly if you need to do a quick, inexpensive, limited repair (one or maybe two flares), on an older car.

The proper way to do this, of course, is with an actual bubble flaring tool. These need not be expensive, and is the way I certainly would have went had I known I was going to do as much of this work as I have done on two cars in the past six months. Going this route, you will (presumably) get the correct flare from the start, and you will avoid any potential problems associated with used rental tools from the FLAPS.
Re: Brake line/fittings sizes....
Tuesday, January 22, 2013 2:21 AM
baron5867 wrote:

When you use the Poly Armour lines, make sure to strip the plastic coating off the end of the brake line before you put it into the clamping tool, otherwise the clamping tool will bite into the plastic and the brake line will slide out as you tighten the press.

I used a file to strip the plastic, but a brass wire brush would probably do a good job.

Also, if you have a long/tedious/complicated brake line to run, consider using multiple sections of line joined by unions to accomplish this.

baron5867 wrote:

Some people on the internet call for use of the flat side of the clamping tool for a bubble flare with a double flare kit, but I did not like this, and use the normal, beveled side of the clamping tool. The rear side of the flare is going to be conformed to the nut when the line is installed and the brake nut is tightened.

You WILL have to tighten the line nuts substantially if you are going to attempt use half of a double flare to approximate a bubble flare. No breaker bars, but you are pretty much going to have to tighten the nut as much as you possibly can with the proper open-end or flare-nut wrench. Avoid vise grips, you can deform the nut, or if it slips, destroy the brake line you just installed.

baron5867 wrote:

Of, as it is now, the lines are installed and I have bled the two rear lines that were worked. The pedal is still very soft. I am assuming that I need to bleed the entire system, starting with the master cylinder.

I bled the whole system, starting at the four connections at the master cylinder. As before, it was a PITA. The tires had to be removed one at a time for access to each caliper or wheel cylinder. The first bleed, at the RR tire, took forever. This is why I originally wanted to plug the lines at the master cylinder.... to avoid substantial fluid loss and the necessity of a system bleed.

I put anti-seize on the brake line at the ends, to prevent any seizing of the nut to the line. I made sure the there was no anti-seize on the front flare surface or on the nut threads. Anti-seize does not belong in the brake fluid.
Re: Brake line/fittings sizes....
Tuesday, January 22, 2013 3:54 AM
I've also heard of the half-double for a bubble replacement.

I'm running a manual setup, so my lines are a mixture of inverted flare and ISO. I used a run of the mill manual tool for this once.... then I got one of these bad boys



it was expensive, but makes flaring lines ridiculously easy and fast. best tool I have ever bought by far.





Re: Brake line/fittings sizes....
Tuesday, January 22, 2013 6:16 PM
DaFlyinSkwirl (Pj) v2.0 wrote:

I'm running a manual setup, so my lines are a mixture of inverted flare and ISO.

The guy who did the hack job mentioned above used inverted flare to patch into the existing brake line, but had to use a bubble flare at the brake hose, so the car had a mixture. I would rather use the same flare type throughout the system.

DaFlyinSkwirl (Pj) v2.0 wrote:

I used a run of the mill manual tool for this once.... then I got one of these bad boys

it was expensive, but makes flaring lines ridiculously easy and fast. best tool I have ever bought by far.

LOL - I don't even recognize that tool from the picture, but I am glad it worked out for you. In my case, the (undamaged) basic kits worked fine once I knocked the rust off of my "skills". By the time I was done with this, I could flare easily, and became more adept at forming the lines.

IIRC, the pros have forming tools (specialized pliers, etc.) that allow them to do professional jobs quickly.

After my experience in the last six months, the brake lines (or at least the rears) should come stainless steel from the factory. It has to be even worse in the rust belt. Brake line ruptures are not fun.
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search