Brake Booster Replacement - a Hint

[geoff]

It gets worse.....................I started the engine to see (hear) if there was any change to the engine note when I depress the brake pedal. There is no change. I don't know if that means anything.
But I then noticed a fuel leak coming from the rubber hose to the fuel rail !!!!!!grrrrrrrrrrrrrrrrr.
I must have cut it whilst pulling on the servo to extract it!
I can see the connector on the end of the hose which connects to the fuel line from the tank, but cannot see how the hose is connected at the other (engine) end. There does not seem to be any connector. (I don't think I am going to like the answer to this question)
happy sunday.
geoff

[18Fiatsandcounting]

It gets worse.....................I started the engine to see (hear) if there was any change to the engine note when I depress the brake pedal. There is no change. I don't know if that means anything.

No change is a good thing. If you had an internal leak in the booster unit, then the idle usually falters when you press on the brake. Since yours doesn't, it appears your booster is OK.

A couple comments on the brake issues you mentioned:
1) I can't speak for an '82 spider, but on my earlier ones, the acorn nut sticks out from the booster front surface about one mm. Since an '82 might be different, you would need to look this up. But there is a spec.

2) If you are not seeing brake fluid coming out of the lines at the wheels, then it's likely your master cylinder isn't pumping fluid yet. The pistons inside the MC travel over an inch, so being off on that acorn nut wouldn't be the problem here. More likely the issue is that your master cylinder just needs to be "primed" to start pumping. Different people do this different ways, but what I usually do is go to the farthest wheel from the MC (the passenger rear), open the bleed screw very slightly, put a long clear hose on the bleed nipple, and suck on it until you see fluid entering the tube. Be careful so as not to end up with a mouthful of brake fluid... You can also use a vacuum bleeder or some sort of vacuum pump for this of course. You many need to do this a bit, go back to depressing the brake pedal a few times, try sucking on it some more, repeat. Another option is to remove the master cylinder to your workbench, add fluid to the supply lines at the top, and slowly work the plungers by hand until you see fluid coming out. Then reinstall in the car.

3) By the way, before I reinstall a new master cylinder (or rebuilding an old one), I usually make sure it's got plenty of fluid in it. New master cylinders that have been sitting on a warehouse shelf for years may be pretty dry internally, which isn't good.

-Bryan

[courtenay]

I gravity primed the m/c by filling the reservoir and opening the bleed screw on the left front rotor. Put some clear tubing on it so the fluid doesn’t leak on your floor.
Once it starts to flow, the m/c should be ready.

[maxm50]

It gets worse.....................I started the engine to see (hear) if there was any change to the engine note when I depress the brake pedal. There is no change. I don't know if that means anything.
But I then noticed a fuel leak coming from the rubber hose to the fuel rail !!!!!!grrrrrrrrrrrrrrrrr.
I must have cut it whilst pulling on the servo to extract it!
I can see the connector on the end of the hose which connects to the fuel line from the tank, but cannot see how the hose is connected at the other (engine) end. There does not seem to be any connector. (I don't think I am going to like the answer to this question)
happy sunday.
geoff

Geoff, don’t worry! All the rubber fuel lines are replaceable. You can buy replacement hose and clamps from the forum vendors... I bought a complete kit from Autoricambi to replace all fuel lines in the car. Any original rubber line (fuel, vacuum, brake, etc) should be replaced.

The original fuel lines don’t use clamps. The replacements do use clamps. Use an exacto knife to carefully cut off the old hoses without marring the metal barbs underneath. Get way up underneath the metal collar, and gently cut/flex/cut/flex until the hose comes off.

As far as priming the MC goes - I bench bled as well as I could without any screw in fittings, which is to say I shoved some vinyl tubing into each of the 3 outlets, topped up the inlets, and gently worked the cylinder back and forth until no bubbles came out. Do the rear brakes (furthest from the booster) first. Then the chamber closer to the booster. Just don’t slip and spray brake fluid all over your wall like I did.

After that I mounted the MC, then stupidly chose that moment to replace the flexible brake lines, which basically drained the MC again, and then a combination of vacuum kit and conventional bleeding got all the air out again. So basically my bench bleed was useless. Also the vacuum bleed kit was useless - I much prefer conventional bleeding.

[geoff]

I will have another try to prime the m/c and the lines.
With regard to the fuel line, are you saying that at the engine end of the hose i it is a 'simple' push on fit?
I have removed the other end in the conventional manor but can not see how to remove the engine end.
Furthermore I cannot seem to find the part listed from my usual suppliers (Vick, Spiderpoint, Middlebatongarage)

[18Fiatsandcounting]

Geoff, just a comment on vacuum bleeding the brake lines. I know some people much prefer this over the method of having an assistant press on the brake pedal while you open and close the bleed nipple and look for bubbles. I prefer the latter, and here's why: The threads on my bleed nipples have loosened up due to age, and so pulling a vacuum on that bleed nipple also draws air past the threads that mixes with the fluid coming out, so it's hard to tell what bubbles are due to air in the lines and what are due to thread leakage. When you force fluid out of the lines by pressing the brake pedal, this isn't a factor.

-Bryan

[geoff]

In case you missed it, I ask again, does anyone know where I can buy the replacement fuel line. I can't see it on any of the usual supplier's sites?
cheers
geoff

[DieselSpider]

If your bleeder threads are not tight enough to get a good vacuum bleed then you really need to replace the bleeders with a sealed set with either an O-Ring or rubber in the threads themselves.



Some will buy a spare set of regular bleeder valves and simply coat them with an appropriate high temperature thread sealant allowing it to dry completely before installing them.

You won't want to pump bleed brakes again after getting things properly set up for vacuum bleeding.

[18Fiatsandcounting]

That's a nice idea, DieselSpider, I like that and maybe will try it one day. I'm not against vacuum bleeding, it's just that the traditional method with pressing the brake pedal has always worked fine for me. By the way, I do start with vacuum bleeding when refilling a brake system that has been completely redone, but then I switch to the pedal method when I get down to the point of flushing out the last of the fine trails of bubbles.

To respond to Geoff's question about the fuel line, what exactly were you looking for here? I've kinda lost track; were you looking for a metal line, standard fuel hose, Fuel Injection high pressure hose, or a special hose with a connector on it?

-Bryan

[geoff]

it is the 'special' hose I require Bryan. It has a screw on connector to the fuel line entering the engine bay but a push on or crimped on fitting to the fuel rail at the engine.

Yes, I too like those bleed nipples. I did no know they even existed.

[18Fiatsandcounting]

Geoff, I wish I could be of more help, but I'm definitely old school with my earlier (carburetor) spiders and it's been 30 years since I've owned a fuel injection model. What I would suggest is giving AutoRicambi or Midwest-Bayless a call, since you've already tried Vick's. AR and M-B are both very knowledgeable and can likely point you in the right direction.

-Bryan

[SteinOnkel]

Geoff, just a comment on vacuum bleeding the brake lines. I know some people much prefer this over the method of having an assistant press on the brake pedal while you open and close the bleed nipple and look for bubbles. I prefer the latter, and here's why: The threads on my bleed nipples have loosened up due to age, and so pulling a vacuum on that bleed nipple also draws air past the threads that mixes with the fluid coming out, so it's hard to tell what bubbles are due to air in the lines and what are due to thread leakage. When you force fluid out of the lines by pressing the brake pedal, this isn't a factor.

-Bryan

The main issue I have with the vacuum method is that the pumps almost always suck. When they fail, you are stuck with a car that can't be driven, yay.

We flush our brake systems before every trackday, so about 8x per year. The two-person method is the most reliable and cheapest.

An alternative would be the Motive Products Power Bleeder. You connect it to the reservoir, pump up the pressure and go through all corners one by one. The only downside is the price. It's $50 with one cap adapter, but an additional cap is $27 which seems outrageous.

Cheers
Steiny

[maxm50]

Geoff, the hose you are talking about is the supply hose to the fuel rail. It has a threaded connection to the hardline going into the body, and a push-on barbed connection to the fuel rail itself. To remove this hose, unscrew the threaded connection (I recommend flare nut wrenches for all connections like this, and a little penetrating oil and a few hammer taps if they haven't been opened in decades), then you will have to CAREFULLY use an exacto knife to cut the hose off of the fuel rail. It's a barbed connection and you don't want to damage the barbs underneath the hose. I recommend a single cut lengthwise along the hose, starting away from the metal and then going all the way to the end of the hose. Use a new, sharp, thin-bladed exacto knife. You'll need to get under the little thin sheet metal "cap" that covers the very end of the hose. Once you have this cut down to metal or mostly down to metal, flex the hose back and forth to open it up, or use a non-sharp screwdriver to pry the cut open further. Twisting the hose to break the seal also helps. Basically you'll need to wrangle the thing to break the 40yr old "bond" between rubber and metal. Once it pops, it's easy to pull off. Note that I did this while the whole fuel rail was out of the car. I imagine it's doable without removing the fuel rail but will obviously be tougher on your knuckles and back.

I do not think it's possible to remove a 40yr old dried out fuel hose without cutting it off, personally.

Anyway, then bring the hose to your bench and cut off the threaded connection in the same way. You should be a pro at it by now.

Here's the hose you need: https://autoricambi.us/fuel-injection-h ... -by-gates/
And get 2x clamps: https://autoricambi.us/fuel-injection-hose-clamp/
Or, just get the kit with enough hose and clamps to replace ALL high pressure fuel lines in the car. These things are 40yrs old, so you really should replace them all. They are now old, brittle, and fragile, as you've discovered. https://autoricambi.us/fuel-injection-h ... t-save-20/

The new fuel injection hose is ever so slightly larger than the original stuff, so it MUST be attached with fuel injection clamps. The original no-clamp method won't work. I read on the Midwest Bayless site that they found it impossible to find ethanol-resistant hose in the original diameter, hence why everyone supplies this hose slightly larger and tells you to use the FI clamps. On my install, I ditched the thin metal caps upon reinstallation.

Follow this same method for any rubber fuel line under the hood - gently cut off of the barbed connectors, cut new hose to match old length, push on to barbs and use FI clamps over barbs to secure.

Hope this helps!
-Max

[SteinOnkel]

Just going to chime in that AR has a healthy markup on these parts.

+1 for Gates though. You can get a 25' spool for like $35 on the interwebs. And a hose clamp kit is like $10.

[tima01864]

Yes, Can be had at your local NAPA