Advice on brake bleeding

Robotsan

Club Member
Hi all,

Just wondering if someone can offer me some advice on bleeding the brakes on my 280z. I found these instructions in the FSM which seems straightforward:

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But just wondering about the bleeder kits, will they all fit the valves on my brakes? Front and back? Or are there specific types/fitments?

Would this do the job? Its only £7 from Halfords! Doesn't seem very "one person" though if you have to press the pedal and keep an eye on the cylinder and the fluid coming out of the callipers?


Or would this be easier? I gather it uses the air from a spare tyre to provide the pressure instead of someone pressing the pedal?

 

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The Vizibleed has a one way valve so you don't need to keep opening and closing the bleed nipple manually, and just have to do the pedal pumping, how well it works I've no idea!

The Gunson Eazibleed wont' work i believe if the 280z has the same twist on rather than screw on master cylinder reservoir caps. Shame as I've used one in the past on other cars and it's quite effective
 
I use one like the vizibleed one (maybe even is vizibleed?) and it works OK, but I never seem to get all the air out on my own - it takes a bit of the Gaskin method with a helper to get it perfect.
 
The Vizibleed has a one way valve so you don't need to keep opening and closing the bleed nipple manually, and just have to do the pedal pumping, how well it works I've no idea!

The Gunson Eazibleed wont' work i believe if the 280z has the same twist on rather than screw on master cylinder reservoir caps. Shame as I've used one in the past on other cars and it's quite effective

Thanks - yeah just found out the Gunson one doesn't work with it!

Vizibleed it is then. Thanks.
 
I use one like the vizibleed one (maybe even is vizibleed?) and it works OK, but I never seem to get all the air out on my own - it takes a bit of the Gaskin method with a helper to get it perfect.

You've piqued my interest.. what's the (Rob I presume?) Gaskin method?!
 
You've piqued my interest.. what's the (Rob I presume?) Gaskin method?!
I think he described it in the other thread: commanding your assitant to press and release the pedal while you open and close the bleed nipple.
 
I’m with Jon on this one - I’ve used several alternatives to The Gaskin and it just doesn’t work as well as getting someone else to pump the pedal! I strongly suspect the nipple is breathing back around the threads when loose. Wasn’t there a one way nipple that people were buying a few tree are back?
 
I’m with Jon on this one - I’ve used several alternatives to The Gaskin and it just doesn’t work as well as getting someone else to pump the pedal! I strongly suspect the nipple is breathing back around the threads when loose. Wasn’t there a one way nipple that people were buying a few tree are back?

Aha, I spotted them but forgot to mention it!

These things?

So does that do away with the bleeder kit altogether? You just connect a pipe from these valves/nipples and into a bucket?
 
Aha, I spotted them but forgot to mention it!

These things?

So does that do away with the bleeder kit altogether? You just connect a pipe from these valves/nipples and into a bucket?
Yep that’s the one! And theoretically yes, but I have no personal experience of how well they work.

Bought one of those. Just not as good as someone pressing the pedal for you! Having used it and found it still slightly spongy, I asked my wife to step on the pedal and some small bubbles still came out of the brakes.
 
Things to consider:

This is a safety related process and if you are a complete novice I would seek assistance from someone who is experienced. You need to be careful with bleed nipples (which can be seized) not to damage them or under/over tighten them. If you 'round them off' or shear them the job becomes more involved.

An experienced 'eye' should inspect the braking system at the same time to establish the cause of the problem.

If you don't know what you are doing you could waste a lot of brake fluid.

Having said the above first of all I would fill the reservoir up to the max mark and then depress the brake pedal and push it hard for 5 mins. Then recheck it and if the level is low again look for leaks - it has to be escaping somewhere.

When you do bleed the brakes ensure that the reservoirs don't run out of fluid - that way you may not have to bleed the master cylinders. It's easy to get carried away and 'pump' a couple of times too many!
 
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Things to consider:

This is a safety related process and if you are a complete novice I would seek assistance from someone who is experienced. You need to be careful with bleed nipples (which can be ceased) not to damage them or under/over tighten them. If you 'round them off' or shear them the job becomes more involved.

An experienced 'eye' should inspect the braking system at the same time to establish the cause of the problem.

If you don't know what you are doing you could waste a lot of brake fluid.

Having said the above first of all I would fill the reservoir up to the max mark and then depress the brake pedal and push it hard for 5 mins. Then recheck it and if the level is low again look for leaks - it has to be escaping somewhere.

When you do bleed the brakes ensure that the reservoirs don't run out of fluid - that way you may not have to bleed the master cylinders. It's easy to get carried away and 'pump' a couple of times too many!

Thanks Rob, really appreciate the tips. I won't be rushing this, and if I get stuck I'll definitely be trying to get someone experienced out to have a look. My brother is very experienced with cars but lives in Norwich so I'll be getting his help with it via video call when I do it.

I'll try what you've advised when I get time on Sunday.

So when you say push it hard for 5 min, you mean push it all the way down once and hold it for 5 min right? No pumping yet?
 
Thanks Rob, really appreciate the tips. I won't be rushing this, and if I get stuck I'll definitely be trying to get someone experienced out to have a look. My brother is very experienced with cars but lives in Norwich so I'll be getting his help with it via video call when I do it.

I'll try what you've advised when I get time on Sunday.

So when you say push it hard for 5 min, you mean push it all the way down once and hold it for 5 min right? No pumping yet?
Yes just keep constant pressure on the pedal. You are seeing if fluid is leaking under pressure.
 
I bought a 100ml syringe to put the fluid into the reservoir as I was a bit nervous about spilling fluid. By coincidence it fitted into the rear reservoir really well and it was just about airtight. This meant I could pressure bleed the front brakes with the help of my son using the open/close method. Front brakes done in about 2 minutes. Backs took a bit longer.
 
Thanks to @Rob Gaskin, I've located the culprit. It is indeed the rear left drum brake.

I filled up the reservoir, did the 5 min brake pedal press, and it then had a lovely firm pedal and the car stopped beautifully on my driveway from about 3mph.

Once I put it back in the garage, the fluid pissing from the left rear was very clear though!

Anyone able to give me a heads up on what might need replacing in there? I've never worked on a drum brake before. So I'll be spending the rest of the day consulting the FSM, Haynes & How To Restore a Z Car book!

PXL_20220828_155216099.jpg
 
Cheers Jon. Is that very likely to be the culprit then?
yeah. The wheel cylinder is the whole thing - there's a piston in the cylinder with a rubber seal. The seal has probably failed, but the cylinder costs peanuts, so IMO not worth repairing.
 
yeah. The wheel cylinder is the whole thing - there's a piston in the cylinder with a rubber seal. The seal has probably failed, but the cylinder costs peanuts, so IMO not worth repairing.

Ok great news, thanks! I may as well do both sides then if they're that cheap.
 
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