The brake booster on my 242 is leaking. I have a replacement that I got from a junkyard. Thankfully the dash was already out so it was really easy. Has anyone replaced this on a 240? What are the recommendations and precautions?

I am concerned with having to remove the master cylinder/break open the lines and have to bleed the system. But at the same time, if it would be better to disconnect the lines so that the brake lines can be left alone and not stressed/broken.

thanks in advance
take care

Luke

The real pain is getting to those 4 nuts on the firewall that are way up under the dash. Besure to check the sealing ring or compound between the booster and firewall. The dual unit allows the booster to be a little smaller. If one diaphram failed the assist would only be half as much.

I agree, don't break the lines. It's too much of a pain to bleed 240 brakes if you don't have to. You shouldn't need to pull it real far out of the way.
Just curious what the booster is doing? They fail so rarely.
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 221K, 88 744GLE- 202K, 91 244 181K, 88 244GL 145K

I would tend to agree, boosters shouldnt go bad. Thats the strange part. I can hear it whistling when the engine pulls more than 15" of vacuum, but above that it goes away. I have not tried replacing the check valve yet but will try soon. The brakes are still fine for the most part it seems to take some more pedal effort than it used to.

are these dual diaphram boosters? I read on thepartsbin.com which has 2 different size boosters dual 8" and single 10" which is why I ask. I wondered if one of the boosters leaks and the other is fine, thereby allowing some booster function but not completely like stock.

The whistling goes away when I step on the brakes a certain amount, if I lightly pressure the brake pedal the whistling changes in tone and amount.
I posted a while back about it leaking after going on a gravel road, dont quite know how the 2 are related. I will change the check valve tonight just to be sure.

thanks all
take care

Luke

The MC will flex out of the way enough to get the booster out. No need to take lines off.That's how I did it.
--
Bruce Young,
940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and going to be crushed unless...)
New 144 from '67 to '78
Used '62 122 from '63 to '67

sweet, thanks. I didnt know if it would, I moved it quite a ways out when removing the booster from the junkyard car.

take care
Luke