Gerald Morris
Senior Member
Felicitations to You Moparians!
Now that I'm getting some control over the engine temperature, I'm starting to look at other systems in states of egregious neglect. ONE of these is the vacuum brake booster! We generally don't like any such thing in our vehicles, but for the sake of expediency and preserving this car's original state as much as possible, I'm willing to consider leaving the Midland-Ross booster in, IFF it WORKS properly! For the present, the booster is on the chopping block.
Hissing brakes when my foot is applied, and they work none too well at that. I see signs that the flipper attempted to rebuild the master and wheel cylinders, but he didn't touch the brake booster, for which, I'm grateful.
Looking in the FSM, one probable source of malfunction might be the check valve. I'm willing to spend ~$10 on a replacement, but NOT $100! Yes, there are highway robbers out in Cyberland jacking folk with prices like $115 for an NOS check valve!
I see that entire, working brake boosters seem rare as boar teats, including even the bottom of the barrel, Cardon't. I'm not subsidizing THOSE criminals again.
So, Dorman makes a generic check valve which looks like it MIGHT fit in place of what's on that Midland Ross booster. Do any of you Mopar Mechanical Sages know if this thing is worth the effort of trying? It runs about $7 at VatoZone.
If that would be money tossed into the gutter, then can the check valve be rehabilitated, say, by spraying a shot of penetrant into it? Or would that aggravate things? I might try that on the morrow.
No question of ONE thing: that brake booster LEAKS VACUUM, and I now suspect THIS is THE MAJOR VACUUM LEAK WHICH HAS DRIVEN MY ENGINE TO OVERHEAT THESE LAST 3 WEEKS!
Note: when I first began driving Gertrude, around the start of October, we got a couple weeks of service from her, and got her through emissions with a remarkably LOW hydrocarbon count in the exhaust, suggesting a VERY LEAN fuel system. She wasn't overheating YET, BUT....
My initial surprise that the miserable power brakes worked at all pleased me at first, but now, that feature has markedly deteriorated. I'm not the least surprised about this: a car which has spent several decades in a barn will be apt to have dry membranes and such. BUT, IFF this is a CHECK VALVE matter, then something might be done without too much effort.
I suspect I'm most likely going to REMOVE that booster this coming weekend. I looked, and see holes which look just right for bolting a Bendix (or any other Mopar type) master cylinder straight to the firewall. These have never been used, but they exist all the same. I expect my 1966 pushrod WILL work in the Bendix master cylinder just fine here, so long as I install the MC properly, sans booster.
If any of you have ideas on this notion, do post them! Again, I'm ALWAYS grateful for responses, even if I occasionally get peeved by a few of them. I freely admit my practical ignorance in many, MANY mechanical matters, as I'm just a blackballed junky engineer, who has done a lot more time as a junky than my papered profession. Thus I try to show some Humility to folks, and admit my faults....
Now that I'm getting some control over the engine temperature, I'm starting to look at other systems in states of egregious neglect. ONE of these is the vacuum brake booster! We generally don't like any such thing in our vehicles, but for the sake of expediency and preserving this car's original state as much as possible, I'm willing to consider leaving the Midland-Ross booster in, IFF it WORKS properly! For the present, the booster is on the chopping block.
Hissing brakes when my foot is applied, and they work none too well at that. I see signs that the flipper attempted to rebuild the master and wheel cylinders, but he didn't touch the brake booster, for which, I'm grateful.
Looking in the FSM, one probable source of malfunction might be the check valve. I'm willing to spend ~$10 on a replacement, but NOT $100! Yes, there are highway robbers out in Cyberland jacking folk with prices like $115 for an NOS check valve!
I see that entire, working brake boosters seem rare as boar teats, including even the bottom of the barrel, Cardon't. I'm not subsidizing THOSE criminals again.
So, Dorman makes a generic check valve which looks like it MIGHT fit in place of what's on that Midland Ross booster. Do any of you Mopar Mechanical Sages know if this thing is worth the effort of trying? It runs about $7 at VatoZone.
If that would be money tossed into the gutter, then can the check valve be rehabilitated, say, by spraying a shot of penetrant into it? Or would that aggravate things? I might try that on the morrow.
No question of ONE thing: that brake booster LEAKS VACUUM, and I now suspect THIS is THE MAJOR VACUUM LEAK WHICH HAS DRIVEN MY ENGINE TO OVERHEAT THESE LAST 3 WEEKS!
Note: when I first began driving Gertrude, around the start of October, we got a couple weeks of service from her, and got her through emissions with a remarkably LOW hydrocarbon count in the exhaust, suggesting a VERY LEAN fuel system. She wasn't overheating YET, BUT....
My initial surprise that the miserable power brakes worked at all pleased me at first, but now, that feature has markedly deteriorated. I'm not the least surprised about this: a car which has spent several decades in a barn will be apt to have dry membranes and such. BUT, IFF this is a CHECK VALVE matter, then something might be done without too much effort.
I suspect I'm most likely going to REMOVE that booster this coming weekend. I looked, and see holes which look just right for bolting a Bendix (or any other Mopar type) master cylinder straight to the firewall. These have never been used, but they exist all the same. I expect my 1966 pushrod WILL work in the Bendix master cylinder just fine here, so long as I install the MC properly, sans booster.
If any of you have ideas on this notion, do post them! Again, I'm ALWAYS grateful for responses, even if I occasionally get peeved by a few of them. I freely admit my practical ignorance in many, MANY mechanical matters, as I'm just a blackballed junky engineer, who has done a lot more time as a junky than my papered profession. Thus I try to show some Humility to folks, and admit my faults....