Allan R

Got to the Olds car show and popped the hood. Everything looked fine except for the master cylinder that decided to die. The pedal was also pretty stiff so I'm figuring that since both are 39 years old, its time to replace them. Just ordered a new brake booster for my car. Got about a week to wait for it to get here. In the meantime I went out in the cave and took a look at how the unit is mounted.
1. No problem undoing the clevis on the pushrod.
2. The 4 bolts that hold the booster? Anyone got any suggetions on how to do that? You gotta have skinny fingers or something to get to them. Maybe a long box wrench? On the passenger side, it looks like you have to take off the washer pump to access the nuts, especially the lower one.

Anyone have any experience with this? Couldn't find any references in the 72 CSM or in any related threads.

defiant1

I used a ratcheting box wrench to loosen those nuts. Difficult to reach, but got the job done. Although I had the hood removed in my case, so I was able to see a little bit better on what I was doing.


d1

Allan R

Hmmm, sounds like an excuse to buy some new tools. And yeah, the hood is still on, that's why I was asking about the ww pump.

edit: Just checked out Canadian Tire. They have OPEN box end ratcheting wrenches on sale for 28.00 for a set of 7. Looks like a neat feature.

my72vert

Deepwell swivel sockets and a long extension

442Harv

All the suggestions are good. I have found the some boosters are different. I had one that sticks out from the firewall a little farther,makes it easier. I have found that you need a long hand swivel, ratchet, a long open handle box end, and a ratchect box end. With the hood off would be a big help. My problem in being older, my eye site is a problem. I now, when I have a engine out, I change the booster, and heater core. So much easier with motor out.

w-30dreamin

Wish I could offer good solid advice but can't remember exactly what tools I used.
I can tell you I have just basic hand tools,nothing fancy.Pulled the swap off,no problems.
During the before hand planning as you are,I thought...crap!this is gonna be a pain. Turns out,it was alot easier than what it looks getting at the booster mounting nuts. I was pleasantly surprised.

Here's a pic of how mine turned out. Get ready to reap the same rewards

DSC02551-2.jpg

442much

Allan, try this. http://www.youtube.com/watch?v=qgf8X4ZzBfg It's even an Oldsmobile.

Lady72nRob71

Ugh... Have fun. 72 CSM simply said "Remove the four mounting nuts". Geez - sounds simple but how to get to them??

I pulled the inner fender....
https://classicoldsmobile.com/forums...tml#post292889
That made getting to the LH side easier.
I got to the RH side by standing in between the fender and the frame. No suspension in the way was a plus. Wiper motor remained there.

Some other firewall parts may need to be removed for clearance, like fan relay.
Use a wire brush on a dremel to clean the threads. Then spray with WD40 afterwards. Let sit over night. If they break free, then they should spin off easily afterwards.

Mine was the "close to firewall" model - a true pain.
I could not get sockets on any of them in any way, and I have lots of varieties.
9/16" box wrenches are the way to go (no 14mm). Ratcheting ones would work well once free. If they are gorilla tight, use long handled box wrenches - they work!
If any start to round, you are in big trouble - get out the dremel and cutters.
https://classicoldsmobile.com/forums...tml#post298896

I finally got the skuzzy bastard out and shipped it off for rebuild. Good riddance...........

Mark71

When I bought my car, my MC was nearly dead and the booster was shot completely.

I did the same job on my 71, without pulling the fender or the ww pump. I first tried to use standard box wrenches - took way too long. Then I got some ratcheting ones from Sears. The kind that look like these are the ones that fit. You'll need the 9/16ths...


The normal box-end, sandwich ratcheters don't fit, the heads are just too wide (ask me how I know). Unfortunately, the USA-made ones are a lot harder to find now. Even Craftsman apparently stopped making them here.

Anyway, to get the lower bolt closer to the passenger's side, I climbed under the car and reached up to it. That seemed easier.

One last thing - loosen the windshield washer pump assembly screws. It'll give you that little bit of extra space that you'll probably need. You can remove it, but I just loosened them enough to shift it upwards. Worked out well.

Anyhow, I put a little anti-seize on the studs and replaced the nuts with matching new ones because the original ones were SO frozen (and painted over, etc.).

And be ready - when I replaced the MC, I found that one of the brake lines was kinked and leaking a little. Long story short, the car has all new SS brake lines, all the way around, with a new prop valve. I got the setup where the prop / combo valve is mounted under the MC - not down on the frame. That makes room for headers.

Here's how mine looks now, sorry for the crappy picture quality.

Allan R

Yup, the master cylinder is actually really easy. The video is a neat link and that's basically how I planned to bench it for installation. Thanks for the thought. My conundrum (fancy big word huh?) is getting the booster off. I can feel the nuts (can't believe I just typed that) but am not sure how to get a wrench onto them.

I really don't want to have to take the fender liner off if I dont have to. That's why I was thinking of moving the wiper motor out of the way. Only 3 bolts to come out..... I suppose that it's really going to come down to who has the most patience; me or the car! I will persevere in the name of my mentor.........

Allan R

Both you and w-30dreamin did a great job. The encouragement and your processes means a lot. Hopefully my fingers won't fail me when I do mine. Can't wait for the parts to get here now.

2blu442

Allen, I've removed these before without pulling the wiper or hood hinge. What I remember the most is that the nuts are really really tight! What I use is two open/box end wrenches. The first I put on the nut, then the second I hook the box over the open end of the first to get leverage. By threading the conventional box end down over the bolt (more like a stud in this application) I don't have to get my fingers in there. The bottom passengerside one is tighter, and I may not have been able to get the second wrench on it. But when your reefing on it think about what your knuckles are going to hit when it comes loose!

Once it's loose you can use a ratchet or ratcheting wrench, whatever will fit. I hold my tounge just right and with the standard box end turn the wrench a tiny bit at a time. After several minutes of this the booster comes off the firewall leaving the bolts/studs from the brake pedal in place. Here's some pic's of what I'm describing



P1010104.jpg

P1010105.jpg

P1010106.jpg

Lady72nRob71

I was doing just that when I was on the lower right one but did not heed the warning. I was too motivated to get that sucker off.
I had the valve cover off (prolly the reason I was able to leave the wiper motor undisturbed).
As soon as the sucker broke free, knuckle kissed corner of cylinder head. That long handled wrench suddenly became the "sonofabitch" tool...
I still wear the scar...

Tony72Cutlass'S'

I think that's exactly what i paid for the ones that i have, those suckers have lasted 2 years now and without a scratch, i dont know why people knock mastercraft all the time, those things are awesome AND i'm pretty sure they're on the lifetime warrenty like the rest of their stock.

-Tony

plee3 64Olds

I removed the WW motor. it helped alot! I had room to squeeze my hand behind the brake booster from up top.

Tony72Cutlass'S'

Not gonna lie, I keep seeing my brake booster when i open my hood, it looks disgusting (Previous owner painted it burnt orange) you guys are making me want to try my hand at loosening those bolts too...

Lady72nRob71

Pull the booster, pull the booster.........................

Tony72Cutlass'S'

Okay, you asked for it Rob... standby, lemme find a picture of what the engine bay looked like when i bought the car..

Lady72nRob71

Holy crap!!
Please post the "after" one now!

Tony72Cutlass'S'

Slowly Slowly i'm getting there.. Rob..

here is a picture of the before and after of the outside too.

Along with a really nice air cleaner that i got from Oldspackrat and cleaned and painted with high temp paint!

Lady72nRob71

MUCH BETTER!!
Wow - that is one heck of a transformation. I know the slow part well - keep it up tho!

Allan R

John,
For some reason, it looks like you have more room than I do...maybe it's just the way the camera was angled.

Ok, you are right. Those nuts are darn tight. I put a closed 9/16 on the nut and snipe on the open end and gave it some oomph. Didn't budge at all. So I'm going to soak it with some penetrating oil for a couple of days to try and loosen it a bit. I don't want to round off the nuts. I probably will take off the ww pump. When I looked it appears there's only 2 bolts instead of 3. ???? did I miss seeing one?

The message in your post seemed to come across as "Take your time and have patience". I think that is wise advice I plan to follow.

Allan R

Yesterday those nuts were so tight not much would move them. Last night and all today it's been raining. Guess what? Maybe the humidity or maybe just good luck. The nuts moved! Leaving them done up till the booster arrives though.

Anyone know why they attached the brake lines to the side of the booster though? What a stupid place to put a bolt/bracket.

Aceshigh

+1

Easiest with the hood off and a ratcheting box wrench set.
Get yourself a set of GearWrench tools. These are the best investment I ever made.

http://www.amazon.com/GearWrench-941.../dp/B0002NYD1C

Lady72nRob71

To reduce the urge to pull the booster...

That clamp bolt came off pretty easy with a 9/16" socket. After the MC is off, the tubes can be move out of the way more.
The tube insulators look like slit fuel line.

Allan R

Whattay think? for 49.95?



I got 3 of the nuts loose. The only one left is the bottom left (under the ww pump). I think the easiest thing to do is just loosen the 3 ww pump screws to give me the room to access that last nut! John's method is working well for me. Although I sure wouldn't mind having a set of these wrenches...

ziff396

I really don't know what the big problem is with the brake booster. It may take alot of 1/8 turns, flipping the wrench to get it loose. Of course mine is not rusted, and just spin them off.

Allan R

Actually it's not a big problem, it's just an annoyance because I really can't drive the car with the brakes not working well. As for the booster, well it's just a tight fit. Glad there's someone else out there who also does 1/8 turns for a while. Good thing I'm not getting paid by the hour

ziff396

I agree about the annoyance. However, nothing compared to removing my dash and re-installing. What a pain in the...

Allan R

I have to do that to. Glad to know its going to be fun.

FWIW, I found that accessing the brake booster from the DS to do those bolts is really easy. The problem I had with the PS ones was I couldn't see them. Problem solved. I took off the air cleaner and stretched out across the top of the engine. Take off the vacuum line from the booster check valve and, Voila! (the vacuum line still had the GM hose clips securing it!) Give a perfect view of the PS Booster nuts. Access is a little tight, but really a lot easier when you can see what you're doing.

Here's a shot showing the master cylinder leak.

IMG_1482.jpg?t=1311612577

Here's what I found when I looked at the booster from the PS. That's why I got the idea of crawing across the top of the engine. ALSO, if you (block your wheels so the car doesn't roll) move the trans selector to L, that moves the trans pushrod tang down and gives extra clearance into that lower left nut area!

IMG_1481-1.jpg?t=1311613219

Mark71

What I wouldn't have paid to have had these pictures about 4 months ago... Nice work!

Allan R

Well it's over. I got my new Brake Booster in the mail today. Morons at the customs office apparently don't have any brains when it comes to opening and repacking a parcel. Turns out their best efforts to trash GM restoration parts aren't good enough - it survived.

It took a little doing to get the nuts off - but they basically just came off by finger rotation once they were loose. The only one that caused me any grief was the bolt holding the brake lines to the booster. Robb - bad boy - I tried to loosed that bolt for close to 15 minutes using your advice. Turns out it's NOT 9/16 as you said, it is 1/2. Oh well, guess that's minor compared to you having to work in 90° heat.

Here's how the changeout finished up.

IMG_1488.jpg?t=1311815680

Thought that was a neat profile shot across the top of the engine. Looks like I'm going to have to dust the engine bay...

IMG_1486.jpg?t=1311816468

The booster is a Delco Moraine GM restoration part. Got it from Crane Corvettes. 164.00 shipped

I didn't like the cotter pin assembly that attaches to the brake pedal, so I kept the old clevis pin and clip. BTW, had fun with the brake lights. Forgot you had to take pressure OFF the switch to have the lights go on. They all work really well. Tested the brakes, they work fine. A little stiff but not bad. I'll have to look up the CSM to see how any adjustments should be made to the brake pedal pushrod length. No problem with bleeding.

I'm going to see about getting my old parts reconditioned. I like the bleeding valves that came with the original Master Cylinder; they aren't on the new one so you have to actually bleed the brake line at the cylinder.

Anyway, I feel a LOT better and have one more thing done on my car. Next: gotta check those front brake hoses, calipers and pads. Then it's off to the drums on the back.

z11375ss

Mines a leakin. Time to change. This is a great thread.