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Hi all - I just rebuilt my master cylinder and thought that while I was at it I would change the 2 lines that go from the master cylinder to that block that is mounted below it. They have the spiral guard on them. I purchased new shinny stainless lines.
But... I can't seem to get those lines out from the block! I was able to disconnect from the master cylinder with our too much struggle... But these two fittings at the block are just not moving. I sprayed a little liquid wrench on it, and I'm using a line wrench, but they are not moving! There is not a lot of room to get leverage either. Any suggestions?
Also, what is the middle connection on that block for? It looks like it could be electrical? How does that come off?
But... I can't seem to get those lines out from the block! I was able to disconnect from the master cylinder with our too much struggle... But these two fittings at the block are just not moving. I sprayed a little liquid wrench on it, and I'm using a line wrench, but they are not moving! There is not a lot of room to get leverage either. Any suggestions?
Also, what is the middle connection on that block for? It looks like it could be electrical? How does that come off?
The center fitting is for an electrical switch. Inside the block is a piston that moves from one side to another if the pressures, for front system or back system, exerted by the master cylinder are not equal. When the piston is off-center, it contacts the electric switch and lights the brake warning light on the dash. I believe the piston also shuts off the side with the low pressure that could be caused by a blown hose or seal further out in the system. There's no need to remove it unless you're replacing it.
If the block is mounted down on the frame, leave it bolted to the frame for increased leverage. If only a couple inches below the master cylinder you're not going to get much leverage, so make sure you use an open wrench or vice grip on the block to help stabilize it. If worst comes to worst, cut the lines you're replacing as close to the fittings as possible and use a socket wrench on them to exert as much torque on them as possible.
Last edited by barkingrats; May 23, 2021 at 09:36 PM.
When you have the old lines out and are installing the new ones, do it with the master cylinder NOT mounted to the firewall (or power booster, if so equipped).
Get the fittings for the lines loosely screwed into the block, and then, with the mast cyl 'floating free', so to speak, you'll easily be able to maneuver the lines and fittings into the MC and get them started in a couple of threads. If the MC is attached to the firewall (or booster) if will be MUCH MORE DIFFICULT to get the lines correctly positioned to get the fittings started in the MC.
If the MC is already mounted, take it off! It's only two nuts, and will save you a ton of time and grief. Been there;done that myself.
Thanks for the tip Larry! That was actually my plan... But right now, I don't know how I'm going to get the old lines out. I'm afraid I'm going to round off that nut.
How does the electrical connector come off? I thought if I can take that off, it might give me a little more room when trying to get the lower connection off.
67:72 gave you good tips about making sure you have a good grip on the block with either vise grips or an open wrench; the lines will be in there TIGHT. And as he says, you can always cut them off to use a socket.
Here are two things that will make access a little easier - with the front end on jack stands, remove the driver's side wheel. You'll be able to sneak in through the wheel well to get a grip on the block. Also, if you haven't already, remove the alternator and it's adjusting arm. That'll give you more room to get at it from the top.
One last thing - I can't speak from experience on this, but I've seen many posts on different forums that say that stainless steel lines make it tough to get a good flare seal. When I replaced mine, I went with standard steel lines (they look great), and even they had to be tightened much more than I would have thought to be necessary in order to get them not to leak.
That electrical connector will pull straight off. Though NOT easily.
If the points on the hex nuts have started to round over, it's probably too late to go at them with the right tool (6-pt crow-foot flare wrench with 3/8" drive socket). You might just have to pull out the big vise-grips, get a good bite into the nut and crack it loose. New nuts & lines will be required after their removal.
If you are going with new lines, anyway, you could just cut thru the line behind the nut and stick a 6-pt socket on the nut.
If the points on the hex nuts have started to round over, it's probably too late to go at them with the right tool (6-pt crow-foot flare wrench with 3/8" drive socket). You might just have to pull out the big vise-grips, get a good bite into the nut and crack it loose. New nuts & lines will be required after their removal.
If you are going with new lines, anyway, you could just cut thru the line behind the nut and stick a 6-pt socket on the nut.
A crow's foot has saved me more than once, as has the cut and 6-point socket.
great tips i learned.. just did this too..i went steel too..and was surprised how tight i had to go.. i even did the inspection and tight loose trick a few times.
this vice grip also a great nut remover.. you are pretty much done with that connector after vice grips..
With stainless steel being harder then regular brake lines, you may have to work the fitting in and out a few times with a Teflon type paste on the threads to get a seal. Getting a good seal drove me crazy. Jerry
great tips i learned.. just did this too..i went steel too..and was surprised how tight i had to go.. i even did the inspection and tight loose trick a few times.
this vice grip also a great nut remover.. you are pretty much done with that connector after vice grips..
What is the "inspection and loose trick?"
So, are stainless lines not a smart idea? I purchased stainless flex lines for all 4 calipers and also purchase stainless hard lines (the short ones) for the two rear calipers. Was this a bad decision?
Can you remove the lines that go to the front and rear brakes? If so, I would just leave it like it is. The blocks function is to light the brake failure light on the dash. It is just a switch.
So, are stainless lines not a smart idea? I purchased stainless flex lines for all 4 calipers and also purchase stainless hard lines (the short ones) for the two rear calipers. Was this a bad decision?
Not sure about the trick mentioned, but stainless flex lines are OK.
From what I've read, the stainless hard lines are difficult to get a good seal because the stainless steel is harder than standard steel, making it more difficult to get a good crush on the inverted flare. And apparently, stainless is also more brittle and possibly prone to cracking in the flare area. Which is why I went with standard steel. And even with those, it took me three times (the final with a fairly healthy 'bop' from my rubber mallet on the line wrench) before I had no leaks.
But to be clear, I've no personal experience with SS; I'm just going by what I've read...on the internet, ya know.
Last edited by Catfish4818; May 24, 2021 at 12:55 PM.
Reason: typo
It seems to me that if you have the lines removed from the master cylinder, you can use a box end by slipping it over the loose fitting, down the line, to the fittings on the block. That will be a more positive grip than a line wrench would.
For ALL flare fittings, it's a good idea to put just a very thin wipe (NOT a gob!) on the fitting threads so that you can easily tighten and seat the flare joint. Snug the joint down firmly, then try the system out to see if 'stuff' is sealed. If not, just give the fitting another 1/8 to 1/4 turn and it should seal just fine. It will also come out MUCH more easily the next time.
Hope the stainless lines fit....dont even try to bend them by hand. If they test fit ok they polish up real nice
Wouldnt do it again but they do look killer polished.
For ALL flare fittings, it's a good idea to put just a very thin wipe (NOT a gob!) on the fitting threads so that you can easily tighten and seat the flare joint. Snug the joint down firmly, then try the system out to see if 'stuff' is sealed. If not, just give the fitting another 1/8 to 1/4 turn and it should seal just fine. It will also come out MUCH more easily the next time.
It doesn't really matter what lube you use...as long as you keep it out of the fluid passage areas. The threaded surfaces DO NOT communicate with the fluid passages. You just need to lube the threads to make it easier to seal the flare joints AND easier to remove the fitting later.
It doesn't really matter what lube you use...as long as you keep it out of the fluid passage areas. The threaded surfaces DO NOT communicate with the fluid passages. You just need to lube the threads to make it easier to seal the flare joints AND easier to remove the fitting later.
Tips for removing brake lines from block?
