Dull Brakes - 79 GTV

[giulia_veloce]

Good thread and lots of ideas.

Maybe get an Alfa person ,specialist to road test it for you.
Have you replaced the brake pads ?
Lots of inferior brake pads out there,,so try a know brand from an Alfa specialist.

Robert

[Cool Jesus]

Keep in mind that your pistons may have seized. Although, it's a little more effort than replacing just the brake lines it may be worthwhile to put a seal kit in. They're cheap enough to source, and since your doing the lines you'll save yourself bleeding the brakes just the one time. How about the booster, was the clunking just the firewall flexing?

[GR-124]

Hi Joe, I currently rebuilding the brake system on my 76 GT and still finding I have a soft pedal. And I don't mean after hard driving. When the pedal is depressed it's just not rock solid like I would have thought it should be. It goes a long way down and only then it has a semi hard feel to it if that makes sense. The car is unregistered so I only driving around the block slowly to test.
I have;
* rebuilt all calipers
* replaced the rear flex hose.
* blown out the solid lines with compressed air.
* removed the compensator valve, washed and blown through with mouth pressure.
* replaced the brake master cylinder, (NB this made no difference the old one must have been OK )
* bled brakes via many methods , pressurised the reservoir, presurised system from the rear calipers, and the two man pedal method seveal times. AND I pretty sure there is no air in the line now.

So I the next thing for me is new front hoses, THEN who knows, I need to get someone else in it that owns an Alfetta to give me there opinion, this, after all maybe as good as it gets.
Joe, I'm not here to take over your thread just letting you and others I'm feeling your pain.

Keep sharing, we'll get there

[festy]

I finished bleeding my brakes this morning after rebuilding the calipers, fitting NOS OEM brake pads, new m/c and resovoir, braided teflon hoses and a fluid flush... but there was more 'bounce' in the pedal than I was expecting
With the bonnet open, standing outside the car and hitting the brakes I could see the m/c flexing upwards, I think I worked out why.
The photo isn't very clear, but the nut holding the bracket to the firewall is loose so the bracket is being levered off the firewall when I hit the pedal. Glad I found that before leaving the garage 

   

[GR-124]

Festy, I did some quick checks for this sort of thing, But I'll have a more thorough look at the mechanical connections from the pedal to the booster.
Good pick up for you

[LukeC]

To all: I agree with Robert, get someone who knows what one of these should stop like to drive it.

Alfettas in their day had good (not great brakes). They suffered from a longish pedal travel compared to contemporary vehicles (probably a somewhat as a result of the cross bar set up etc). When the system is good, they will lock their brakes at lower speeds easily with very good weight and modulation, but fade resistance is not the best. Hard pads/glazed discs were common problems when I worked on these (often resulting in poor fade resistance too). Easy to fix with pads and discs. Just a fiddle with a screw driver to see if the pads/pistons retract easily will give an indication is the calipers need rebuilding. A car with a stuck caliper will pull one way or other usually rather than just have dead brakes.

A semi-hard feel with spongy brakes is when one circuit has air and the pistons are behaving like one circuit has failed (they contact eachother, partway through the full stroke).

The rear calipers are notoriously difficult to bleed. My most successful technique is the jack the rear of the vehicle up as high as you possibly can and pressure bleed (I have an old cap that I can set up to my air compressor while the regulator is set at about 3 PSI). You will have to repeat the process a few times to get the pedal prefect (driving the vehicle in between bleeds).

The boosters are prone to going. Pump the brake pedal a few times with the engine off to evacuate the booster: start the engine with the pedal depressed. The pedal should go down to the floor somewhat, and not pulse (if it does, this means the booster diapragm is cactus). If it does not pulse, turn the engine off and see if the pedal comes back up at you (if it does this could mean a leak on the vacuum side of the booster, the diapram has just gone or the MC "O" ring or the one way valve at the inlet manifold - but these are pretty reliable). You should be able to turn the engine off an get a few assisted pedal strokes out of the booster before the vacuum is exhausted (listen and feel for it).

I have an excellent booster off my '85 GTV if someone needs it.

 

[giulia_veloce]

Well said Luke C

Yesterday I completed a front + rear caliper overhaul + new  KNOWN brake pads + bled the brakes.
Not a great pedal but was ok.
Went for a few laps around the block and the brakes started working and the pedal improved.
Sometimes you need to bed the brakes in properly before you get a good pedal.
After about 20 or so slow brake applications,the front of the car dived to the point of just locking the front brakes.
Generally with Alfettas + their inboard rear brakes,after bleeding and adjusting the rear calipers,its a good idea to bed in the brakes on the hoist= a few good brake applications,then maybe rebleed + adjust the calipers again.Handbrake cable is the last thing to be attached.That way,the rear brake pads are sort of bedded in before a good roadtest.
What I am saying is,go for a few laps around the block before saying the brake pedal travel is too long.
Bed the rear brakes in on the hoist or jack stands before roadtesting.
Luke C an I have had many years fixing these cars,and sometimes brakes can be cured by replacing the pads with good quality known ones,a good raodtest,and properly adjusting those rear brake calipers.
Lately have changed many a rear brake flexible line due to not enough fluid coming out of the bleeder nipples and the pedal very slowly going to the floor while bleeding= not much rear brakes happening.
As Luke C said,,Alfettas should be able to lock the front brakes with a heavily pushed pedal,but correct type brake pads should be used,and only after a good roadtest and bedded brakes.
Flexing firewalls around the booster is normal,and should not need repairs for a road car.

Robert

[joestram]

Wow - thanks for all the comments guys.

I am going to try and replace the front pads to see if that makes any difference.

Does anyone know where I can get a set of Ferodo DS2500 locally?

Also, how hard is it to replace the front discs as a beginner?

Thanks guys.

Joe

[GTVeloce]

Hi Joe

Front discs are also fairly easy from memory. Pop the wheel off. Remove the pads. Loosen the two bolts that hold the calliper but you don't have to remove them. Then there is two flat head screws that hold the disc to the hub and hey presto. Fitting is the opposite of removal.

Can I suggest the following book?
http://www.pitstop.net.au/products/alfa-romeo-alfetta-and-gtv-1973--1987-repair-manual/

I have certainly studied it cover to cover and I'm sure many others here have too.

Cheers
Julian

[joestram]

Hi Julian,

Thanks for that and thanks for all your information yesterday!

I have that book but I find it hard to exactly see what they are explaining as they the pictures are dark and black & white.

I will definitely try what you mentioned yesterday and report back.

Thanks Julian

[joestram]

So does anyone know where I can get some ferodo ds 2500?

Will I need any copper grease for the back of the pad?

Thanks

Joe

[Cool Jesus]

I would put some grease, but that's just me. It's not a nececity with all pads, but if the squeal it can be sorted with a just a light smear where the caliper piston contacts the pad. I do it as smattering of course as it doesn't hurt anything and it saves pulling the pads out again if they do squeal. Good pads these days come with a Teflon/polymer film on the back to minimise squeal. The grease will help a little in reducing friction between these two components, letting the pad bed into the disc to settle itself in and not have to hard surfaces vibrating against each other to emit the squeal we hear.

And yes, as mentioned earlier, many issues are subjective. Although I see this isn't your first Alfetta. If you post your suburb, I'm sure another board member can message you to tee up a test drive and diagnose the issue on an objective level with you.

Wouldn't hurt to, go old school and ring around in order to locate the pads you're after. Especially club sponsored guys, domenic at Italian auto spares comes to mind. I'm guilty of always seeking an answer on line rather than calling someone, we certainly are an online society these days.

[hammer]

Joe,

Richard Anderson from Avanti Spares in Brisbane (long time club member and supporter) sells 2500s and he'll ship them to wherever you are. His number is 07 3266 6623. He has also rallied various Alfettas for more than 30 years and knows these braking systems intimately.

Cheers,

Brent

[Cool Jesus]

Hey joe found this thread which may provide some further insight.

http://www.alfaclubvic.org.au/forum/index.php?topic=6532.0