Ontopic The new car-seching thread

Hoff Kinkmeister

never met a virtue I wont signal
Apr 16, 2016
11,459
10,562
373
Is there some kind of small(ish) Rover coming out? Saw something that had their ass in dazzle wrap, looked as wagon as anything can these days.
 

Mean Mr. Mustard

Always shouts out something obscene
Sep 30, 2004
68,867
37,175
1,323
52
Uranus
Steam
heyfubuddy
car deal with it GIF
 

Mr. Argumentor

Will Argue for Tacos
Sep 27, 2012
51,822
23,836
723
Tampa-ish
Steam
asastang
Had a car take out a power pole yesterday about an hour after I left work. Strange thing is it broke the opposite direction from traffic and about 15-20 feet off the ground. No clue how they did it.
I'll try and get a pic from a coworker that was working late.
 

Hoff Kinkmeister

never met a virtue I wont signal
Apr 16, 2016
11,459
10,562
373
Had a car take out a power pole yesterday about an hour after I left work. Strange thing is it broke the opposite direction from traffic and about 15-20 feet off the ground. No clue how they did it.
I'll try and get a pic from a coworker that was working late.
Maybe it was flexible enough to bend, but then snapped as it righted itself? IDK I saw a sword break like that on some video. Like it got all wiggly and then a weak point failed and the wiggles above the break pulled it back.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
I'm finding alternating theories here, so does anyone know whether I should be able to take the master cylinder off my brake booster without the booster leaking air?

Because it's a leaker. Slower if I bolt the master in securely with some O-rings in the groove, faster if I don't.
 

Mr. Argumentor

Will Argue for Tacos
Sep 27, 2012
51,822
23,836
723
Tampa-ish
Steam
asastang
I'm finding alternating theories here, so does anyone know whether I should be able to take the master cylinder off my brake booster without the booster leaking air?

Because it's a leaker. Slower if I bolt the master in securely with some O-rings in the groove, faster if I don't.
You can 100% remove the MC from the booster without it causing a leak. How are these others thinking that you change either of those parts when the other isn't bad?

:wtf:
 

ZRH

(retired?) Google-F.U.
Mar 5, 2005
23,199
1,359
573
<3
I'm finding alternating theories here, so does anyone know whether I should be able to take the master cylinder off my brake booster without the booster leaking air?

Because it's a leaker. Slower if I bolt the master in securely with some O-rings in the groove, faster if I don't.
Are you high? :confused: What the otherdude said.

*thinks* yeah it's a vacuum on the cylinder side
 
Last edited:

Mr. Argumentor

Will Argue for Tacos
Sep 27, 2012
51,822
23,836
723
Tampa-ish
Steam
asastang
The vacuum side is the side against the master cylinder. The vacuum assists in pulling the rod into the cylinder, after all.
There's vacuum on both sides till the pedal is pushed apparently. I always thought one side was permanently sealed. Need to review how the pedal side gets that vacuum without both sides being lost when the pedal is pushed. Check valve somewhere?

Anyways, not important right now. Point still stands that they wouldn't design it so you had to replace both if only one got fucked up, at least not with stuff as old as yours.
If there is corrosion around the sealing surface, that may cause you to lose the seal.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
There's vacuum on both sides till the pedal is pushed apparently. I always thought one side was permanently sealed. Need to review how the pedal side gets that vacuum without both sides being lost when the pedal is pushed. Check valve somewhere?

Anyways, not important right now. Point still stands that they wouldn't design it so you had to replace both if only one got fucked up, at least not with stuff as old as yours.
If there is corrosion around the sealing surface, that may cause you to lose the seal.
Um, there's only vacuum on the master side. Not sure where you're getting that.

Point doesn't stand, as I can replace either without consequence to the other component in the chain whether there's an air leak or not.

This is why I'm confused. So much wrong information going around.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
At any rate, it was $150 for a new booster through "The Right Stuff", which is the same company I bought the rear disk conversion from, so I trust them. It'll get here this week and I'll try it out in the ol Goat.

Put the vacuum pump for the brakes back in, but it's nice and hidden this time. Made a bracket that hangs the vacuum sensor off one of the mounting ears for the master cylinder, and put the wiring and relay for the pump under the driver's fender. Re-ran the PCV to the back of the throttlebody and capped off some holes in the intake manifold, which cleans things up nicely, I think.
283871606_10159733085324342_1985521114246606238_n.jpg
 

Mr. Argumentor

Will Argue for Tacos
Sep 27, 2012
51,822
23,836
723
Tampa-ish
Steam
asastang
Um, there's only vacuum on the master side. Not sure where you're getting that.

Point doesn't stand, as I can replace either without consequence to the other component in the chain whether there's an air leak or not.

This is why I'm confused. So much wrong information going around.
If there were vacuum on both sides the brakes would always be applied. Draw a free body diagram.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
oh, and I went ahead and ordered a 1" smaller water pump pulley for the damn thing too. It was pretty toasty yesterday on a drive.

Probably should just convert to the 11 bolt water pump and timing cover that Pontiac put on after '68, but I'll see if a $55 solution will work before dumping into the $1000 solution.
 

gee

Blame It On The Gassa Nova
Sep 29, 2012
16,268
18,080
373
Halifax
there's a big spring on the vacuum side.
Both sides of the brake booster get vacuum. The engine sucks on the master cylinder side of the booster, but there's a small hole that slowly equalizes the pressure on the pedal side.

When you push the pedal it opens the pedal side to atmospheric, and suddenly there's atmospheric pressure on the pedal side of the diaphragm + vacuum on the master cylinder side. That pressure difference now pushes the diaphragm and gives you your braking boost.

Leaks on any part of the booster will cause a vacuum leak. Might as well replace the whole thing like you just did.
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
and right on cue, the bottom bolt for the water pump has stripped threads.

I'm sick and tired of finding this shit out this way.

Looks like I'm pulling the timing cover so I can helicoil the bastard. Shame all my helicoils are metric, guess I'll get the collector's edition on amazon for SAE sizes now.
 

ZRH

(retired?) Google-F.U.
Mar 5, 2005
23,199
1,359
573
<3
and right on cue, the bottom bolt for the water pump has stripped threads.

I'm sick and tired of finding this shit out this way.

Looks like I'm pulling the timing cover so I can helicoil the bastard. Shame all my helicoils are metric, guess I'll get the collector's edition on amazon for SAE sizes now.
Cant you tap it?
 

Jehannum

HO HO HO METH GIANT
Jul 24, 2013
43,318
44,470
723
41
Albuquerque, NM
Cant you tap it?
I tried running my tap down it. It's the bottom left one in the picture (labelled "wp").

Pontiac-400-Timing-Cover-Bolt-and-Size-Locations.jpg

The tap gets to the bottom of the hole before getting any purchase on the threads.

I'll have to take the timing cover off, replace the gaskets, the front main seal and helicoil the hole.

Fortunately, it's all cast iron, so I don't have much to worry about really. The oil pan seal and the front main were kinda suspect anyways, so it's probably better this way.
 

ZRH

(retired?) Google-F.U.
Mar 5, 2005
23,199
1,359
573
<3
I tried running my tap down it. It's the bottom left one in the picture (labelled "wp").

View attachment 16138

The tap gets to the bottom of the hole before getting any purchase on the threads.

I'll have to take the timing cover off, replace the gaskets, the front main seal and helicoil the hole.

Fortunately, it's all cast iron, so I don't have much to worry about really. The oil pan seal and the front main were kinda suspect anyways, so it's probably better this way.
Ah. Well at least it isn't any of the electronic shit they stuff into cars these days. Relatively straightforward fix compared to running down every cable harness in the car.