Ok guys, what in the world is this big black metal part that I have circled. What is it, what's it do, and how do I get to it!

I just noticed that is has also developed a little rust spot! Nothing annoys me more than rust as we discovered in a more recent post. (more on that next week...)

I want to fix this ASAP. What does it involve.

 

That is the brake vacuum booster. You'll probably need to remove the master cylinder, and intake manifold to get a clear shot at that rust spot to clean it ... removing the booster from the car would be a real PITA I suspect.

That has to be the cleanest engine bay I've ever seen! that rust would be maddening I suppose.

 

The power brake booster?

Have fun.

http://www.clarks-garage.com/

 

Tony,

There is a thread by Geo about that very item, the brake booster. The only way to get it out is to remove LOTS of stuff, short version. https://rennlist.com/forums/924-931-944-951-968-forum/230130-these-cars-were-designed-by-a-sadist.html < long version.

Grab some sand paper and get to it.

I am looking forward to seeing this rusty spot this sunday! Remind me if I forget to ask. BTW, what time were you planning on going?

Michael

 

You more than likely have a seal in the back of the master that is bad, has been bad at some point. That is the only thing that I have ever seen that causes it to rust like that. Unless you spilled brake fluid and wiped every where else. Pull the master off and make sure it is not wet behind. I suspect you can pull it out far enough without taking the lines loose. Then you can also tape it off and sand and paint if there are no leaks.

 

Wow, good look'n bay. Maybe a Dremel with the cable driven remote? Take pics of the masking job, heheheheh.

POP, hows the dash? See the post I resurrected about the 930 grills!!!

 

Sure did. Dash looks fab., seats need to be buttered up, BBS RS wheels showed up yesterday, my white-on-black 924s gauges should show up today.

 

THE understatement of the year--that engine bay is Breathtaking!!!

 

Depends on where the rust spot is. If it's on the outer surface of the black can it might just be some spilled brake fluid. That stuff removes paint in no time. It could be a bare spot from the PO who changed it out after a leak. I would not remove it unless you can confrim it's leaking now.

 

I have seen it leak in the back and come around and down the front on more than one occasion. I would deffinetely look into it.

 

Wait, if it was leaking...I would be loosing fluid correct? I would have noticed that. I think its an isolated spot that fell. That makes sense now. Would the POR15 stuff work there just as well?

 

POR 15 is for stuff much worse than what you have shown. If you have it already for the battery tray issue you may wanna give it a try but I am guessing that you will want the smooth glossy finish of the original coating. That will be tough to achieve I think. What you need to do is lightly grind/sand it down and figure out what you are actually working with. You could just re-seal the area with a good etching primer and paint it. If it is surface rust it really isn't a big issue.

Michael

 

Good advice. POR-15 is overkill and is not a rust converter, it just encapsulates the problem. Good surface prep is your best course of action if it's just chemically damaged paint and a typical surface rust bloom.

 

Paint it... with a semi-gloss black paint?

 

Sand it, down to a point that you can no longer see ANY rust. Take a look at things and determine how bad it really is. Take your sanding patern out about an inch or two JIK. Use a quality etching primer to seal/set the surface up for a sandable finishing/primer. Work out any rough or raised edges. Paint the area sand and polish. Best guess for a good job is 2 days allowing for drying time between coats of paint. Your total invested time should be less than 2hrs. You have a sharp looking engine bay, let's try to keep it that way.

Mattos is a great source for supplies.

Michael