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I'm going to replace my master cylinder. But before I do I want to know if someone else has changed theirs out. Once I remove the nuts from the mounting ears I have to wriggle off the bracket (#1) that sits in front of it. The RWAL module and proportioning valve (#'s 2 & 3) are attached to that bracket. Of course I will have disconnected the two brake lines from the master and I'm thinking there should be enough play in the remaining brake lines to pull that bracket off the mounting studs without having to detach the RWAL and proportioning valve lines/fittings. The FSM suggest those lines might need to be detached.
Plenty of wiggle room on those lines to just move it out of the way. If the lines below them are crusty though, they might break. Just be careful.
Yeah, not too crusty. It's lived most of its life in the south in a garage so crustiness is at a minimum. However, this was not the case when I changed out my brake hoses. Every dang brake line twisted and snapped when I unscrewed the fitting. I'm expecting the same when I remove the fittings off the master unless I can learn a new trick (other than a week long bath it PB Blaster). Maybe, break the fitting loose then go back and forth? I'll accept any tips and tricks to get those brake lines to free from those fittings.
Yep, chems, use a line wrench (if you have one) to get it to break loose, then more chems, and wiggle it till it turns easy. If the line starts to twist, STOP, more chems, wiggle some more.
Yep, chems, use a line wrench (if you have one) to get it to break loose, then more chems, and wiggle it till it turns easy. If the line starts to twist, STOP, more chems, wiggle some more.
I'm not as worried about removing the nut from the master as I am the brake line being corroded inside the tube nut then twisting and snapping the brake line. That's how all my other brake lines broke. The brake line and tube nut became one.
I have one line wrench I inherited from my dad. 7/16 x 3/8. It worked on all my brake lines. I'd rather be lucky than good. LOL! However, that wont work for my master. I'll need a 9/16 line wrench. I suspect a 14mm would work too. I agree, a line wrench on a 29 year old vehicle is the only way to go. Especially if you live in Michigan.
Another problem I have is I need to buy new tube nuts and they're not easy to find in the sizes I need. 1) as a backup in case removing the ones I have get destroyed whilst taking them off the master (good chance), and 2) to make my own bleeding lines for when I bench bleed the new master. My master uses two different sizes and they aren't exactly common. One is a 1/2-20 and the other 9/16-20. Both for 3/16" tubing. RockAuto carries every size but those. Trying to find them on Amazon. Any idea where else to look?
UPDATE: I found some inverted tube nuts in the sizes I need on Amazon.
Be sure to use the proper line wrench. Swapping between metric and SAE often works, but not a good idea on brake lines. Your lines look good but you might want to wire brush the lines anyway. A little trick I use on brake lines is a hammer. Not a big one. I have a brass machinists hammer. I tap around on the nut and line where everything goes together. Then I put pressure on the wrench to remove the nut. It may pop loose but a slight rap on the end of the wrench can pop it loose. You want lots of penetrant on the nut threads and also on the line where it goes into the nut.
As for thw bracket, your lines don't look rusty so it ought to slide right off the bolt threads and go back on with some body English.
Be sure to use the proper line wrench. Swapping between metric and SAE often works, but not a good idea on brake lines. Your lines look good but you might want to wire brush the lines anyway. A little trick I use on brake lines is a hammer. Not a big one. I have a brass machinists hammer. I tap around on the nut and line where everything goes together. Then I put pressure on the wrench to remove the nut. It may pop loose but a slight rap on the end of the wrench can pop it loose. You want lots of penetrant on the nut threads and also on the line where it goes into the nut.
As for thw bracket, your lines don't look rusty so it ought to slide right off the bolt threads and go back on with some body English.
Good idea on the hammer taps. I have a small tack hammer I could use.
I have one of those bisexual trucks. Some of it is SAE and some of it is metric. I usually have to try both to see which fits best. Sometimes it’s spec’d as an SAE but the metric still fits better. According to the chart on RockAuto, the Raybestos master I bought is SAE. I bought a cheap 3-piece line wrench set so I should have the sizes covered.
I’m gathering the best approach is to finesse those tube nuts and brake lines as much as possible using a good dose of patience.
If I end up snapping those.brake lines at the master I have to decide if I want to replace the entire lines from the master to the proportioning valve or splice in a new piece. I see pros and cons both ways. One concern is how hard will it be to de-nut at the proportioning valve. Not much meat to work with there.
Good idea on the hammer taps. I have a small tack hammer I could use.
I have one of those bisexual trucks. Some of it is SAE and some of it is metric. I usually have to try both to see which fits best. Sometimes it’s spec’d as an SAE but the metric still fits better. According to the chart on RockAuto, the Raybestos master I bought is SAE. I bought a cheap 3-piece line wrench set so I should have the sizes covered.
I’m gathering the best approach is to finesse those tube nuts and brake lines as much as possible using a good dose of patience.
If I end up snapping those.brake lines at the master I have to decide if I want to replace the entire lines from the master to the proportioning valve or splice in a new piece. I see pros and cons both ways. One concern is how hard will it be to de-nut at the proportioning valve. Not much meat to work with there.
My hammer is brass so it doesn't hurt the aluminum. I've found that a lot of cars and trucks starting in the 1980's and going into the 90's, have a mix of fasteners. Generally, body parts are metric and mechanical parts are SAE. Mechanical components like alternators can be either way. Then again, I still count battery caps. Everything now is 6 cells, but I'm old and am used to stuff that may, or may not, be 12 volts.
On the really short lines to the proportioning valve, if one breaks, just replace it. Get a tubing bender and use a longer line with a coil to take up slack. Don't cheap out on brakes unless you want to use a crow bar to go to the bathroom sometime down the road.
3536885[/url]]My hammer is brass so it doesn't hurt the aluminum. I've found that a lot of cars and trucks starting in the 1980's and going into the 90's, have a mix of fasteners. Generally, body parts are metric and mechanical parts are SAE. Mechanical components like alternators can be either way. Then again, I still count battery caps. Everything now is 6 cells, but I'm old and am used to stuff that may, or may not, be 12 volts.
On the really short lines to the proportioning valve, if one breaks, just replace it. Get a tubing bender and use a longer line with a coil to take up slack. Don't cheap out on brakes unless you want to use a crow bar to go to the bathroom sometime down the road.
Well, it’s not a matter of being cheap. I’m just thinking removing the tube nuts off that proportioning valve could be a PITA.
I can’t detect a pattern on my truck w/regard to SAE and metric. My lower control arm bolts took metric. The upper control arms took SAE. Maybe my truck was built when the regular control arm assembly tech was on vacation.
02-04-2022, 11:31 AM
Master Cylinder Replace
