After some research here on Mud, I took the plunge and swapped out the dead brake booster on my 1980. The donor vehicle was a 1987 Toyota pickup from the local salvage yard. Total price of replacement booster $15.
It was a snug fit, but it bolted right up. Here is a picture of the finished product. It works great.
The replacement booster has a slightly larger circumference than the original. Once in, there is barely 1/4 inch of clearance between the booster and the clutch master cylinder reservoir. And that 1/4 inch did not really show up until the the booster was snugged up to the firewall. All's well that ends well, but it made me a little nervous during the install.
The circumference of the replacement is 30 inches.
The circumference of the original is 27.5 inches.
A 30 inch will fit, but I would not recommend anything larger. Watch out for this as you seek a replacement. (Maybe 30 inches is as big as Toyota gets.... not sure.) Depth doesn't seem to matter much. As others have noted, make sure the master cylinder side of the replacement matches your MC bolt pattern, get the firewall spacer with the replacement (if it has one) and the check valve if it is not built in. I had to cut off 1/2 inch of the rod that connects to the brake pedal to match original rod length.
I did not disconnect any brake lines during the install. I just eased the brake MC back enough to get the original booster out and eased it forward to connect to the new booster. If you use a 30 inch replacement booster, I would loosen up the clutch MC to give you a little extra room during the install.
It was a snug fit, but it bolted right up. Here is a picture of the finished product. It works great.
The replacement booster has a slightly larger circumference than the original. Once in, there is barely 1/4 inch of clearance between the booster and the clutch master cylinder reservoir. And that 1/4 inch did not really show up until the the booster was snugged up to the firewall. All's well that ends well, but it made me a little nervous during the install.
The circumference of the replacement is 30 inches.
The circumference of the original is 27.5 inches.
A 30 inch will fit, but I would not recommend anything larger. Watch out for this as you seek a replacement. (Maybe 30 inches is as big as Toyota gets.... not sure.) Depth doesn't seem to matter much. As others have noted, make sure the master cylinder side of the replacement matches your MC bolt pattern, get the firewall spacer with the replacement (if it has one) and the check valve if it is not built in. I had to cut off 1/2 inch of the rod that connects to the brake pedal to match original rod length.
I did not disconnect any brake lines during the install. I just eased the brake MC back enough to get the original booster out and eased it forward to connect to the new booster. If you use a 30 inch replacement booster, I would loosen up the clutch MC to give you a little extra room during the install.