Daniel5691

Hi !

1981 928S Euro, 5 Speed Manual, LSD, KJET/CIS

So my poor leaky engine is out, and I am now inspecting the brake system in the engine bay.

"Way back when" the 928 was running,
the brakes were functional,
but the pedal was slightly "soft" on the first 2-3 stops,
but then would firm up substantially.
It felt as if it "might" need bleeding... but nothing terrifying on driving.
BTW, the clutch seemed to operate OK,
with the exception of harder 1-2 and 2-3 shifts until she was warmed up; but clutch pedal 'feel' seemed consistent.

So here is my first clear look at the engine bay brake components.....

MY QUESTION: What is a common-sense approach to the engine bay brake and clutch component WYAIT task list?

In other words, what should I do?

My very sincere thanks for your time and advice. What a forum !

Crumpler

Hey Dan, I would replace the famous blue hose, check valve on the brake booster, blue check valve (but it looks new--replaced already?), there is a gasket between firewall and booster if memory serves, grommets between the resi and master, R/R resi -- I can't remember what Stan recommended to clean it with, but it worked like a charm.

Hell, if you are all in, I would take the opportunity to pull the A-arms on your suspension and replace the bushings WYAIT.

Happy Hunting.

ltoolio

Stan's cleaning routine:
https://rennlist.com/forums/928-foru...l#post10217675

GlenL

The brake master symptoms don't sound like air. I'd strongly consider replacing the brake master.

I'd also replace the clutch master and the blue hose. It's not expensive and simple to do with the engine out.

OTR18WHEELER

FIFY

The Forgotten On

Replace EVERYTHING. That is what I say if you can afford it as now is the easiest time you will have to replace any of the components.

At least replace the masters and the blue hose minimum as they are a bitch to replace otherwise. Ask almost anyone on this board with a 5 speed, they'll know the pain.

OTR18WHEELER

I. Fify'd that to say this....
Terminology matters...
The reservoir for the brake system is the master cilender, the manual transmission cars have a SLAVE cylinder for the hydrolic clutch, not being racist, that just how they are identified.

MainePorsche

Now with engine out I would replace/service every component now easily available that you have not already recently done. Do all that you can. You won't very often have this opportunity.

The Deputy

Me...I'd remove the booster/master cylinder and slave cylinder to have rebuilt. Also, replace the blue hose while it's apart and any steel lines that look suspect.

And, since the cap is off the reservoir and contaminants and condensation have probably compromised the brake fluid...flush the whole system.

Now is the time, especially for that blue hose and removing the necessary items to get at it. You will be very, very sorry if you don't do it now. Having the engine back in will only lead to more difficulities.

Brian.

MainePorsche

^^ +1 'especially for that blue hose...'
The other PITA issue that would be good to do with the engine out is the coolant reservoir and its hoses beneath it. If reservoir is not problematic that is good but do the hoses at least. Also good be a good time time to replace the coolant level sensor as preventative measure - reservoir has to be at least released for this.

kawi825

I did new slave, master, blue hose,fluid flush. ALSO, wyit replace the grommets under the reservoir. I didn't think of it and mine was wet under the reservoir probably from being disturbed so much and dried out. Got two new grommets from roger dirt cheap and two year later nice and dry. I had a little bubble trapped when all done. Burped the slave cylinder down at the bell housing with a screwdriver and works perfect now.

kawi825

Oh and I did it all while the engine was in and car on jack stands- TERRIBLE. So great that you have engine out.

GlenL

NO!

The MASTER is accessed from the engine bay. The SLAVE is on the clutch housing and is easily accessed.

This does suggest doing both MASTER and SLAVE and the BLACK HOSE that is in between. Add the BLUE HOSE and you're set for years of clutching pleasure.

Daniel5691

Thanks so much for the input thus far....
I am definitely leaning toward replacing as much "replaceable" hardware as possible.
But with no real experience, I am trying to decide where to draw that line....
Your comments definitely help me with the decision process.

Brian, what a sharp eye !! Wow !
(I had removed the reservoir cap just prior to snapping the photos,
I thought one of the gurus may be able to glean some info from some detail of the cap/ filler area LOL)

I am concerned about the visible surface corrosion on the brake booster assembly, as well as around many of the line fittings.

Not to hijack my own thread, but it seems that I am following a
"plug-and-play" strategy with many of the tasks on the car.
I am less confident in my ability to correctly REPAIR or REBUILD a component,
and more inclined to just take the "old thing" out and put a "new thing" in...

Again, thank you for your time and insight....

toofast928

And when your all done, before the engine install wrap all brake lines and components with heat wrap like DEI velcro.