Brakes

[tim hunt]

On 8/3/2023 at 6:48 PM, ianc said:

Peter: the standard procedure is to start with the furthest away, so surely the sequence is: L Rear, Right Rear, Left Front, Right Front.

Clearly, this is the sequence which Andy and I have been using for decades, and my Workshop Manual states that one should start with the wheel cylinder furthest from the master cylinder, finishing with wheel cylinder nearest the master cylinder. 

Because the WSM was written for Great Britain, it refers to Nearside and Offside - terms which I dislike and never use.

Ian Cornish

When referring to 'furthest away' from the M/C the consideration should not be 'As the crow flies' but should take account of the length of pipe run from the Cylinder to each wheel. I agree with Ian's order for the TR4 but for the 4A with IRS the order should be R Rear, L.Rear, R.Front, L. Front, as can readily be appreciated from the diagrams on pp60 and 61 of the Moss catalogue. 

I fitted ABV automatic bleed valves to each wheel and the clutch slave cylinder fifty years ago and they are still functioning perfectly and make bleeding a simple one man job. I am surprised they are no longer widely available. Once upon a time they could be found gathering dust in old school motor accessory shops or at auto-jumbles.

Tim

Edited August 7, 2023 by tim hunt

[ianc]

I am sure that Tim and PeterW are correct that for the TR4A the order at the rear is reversed.   Now, having looked in the Parts Manual for that model, I can see that they are correct.

At the NEC Show in November 2016, I purchased four automatic bleed valves from Automec for total of £12.   A bargain - but it seems that they no longer make/supply them and, despite my comprehensive location list of all the parts in my garage, I have not found them.

They are quite small and must be hiding from me, which is very annoying as I intended to fit them later this year!

Ian Cornish

[Terry Potter]

Thanks all for your help, not managed to get back on it yet, but will try all that's been mentioned,  I omitted to say it's A TR4A IRS, so may do it as Tim Hunt suggested

I will let you know once I'm able to get on it.

[Tr4aJim]

One “advantage” to having a solid axle TR4A - only 3 bleed screws!

Jim

[ianc]

I am puzzled - how does one ensure that all air is expelled from both left and right slave cylinders on a solid axle TR4A if there is but one bleed screw at the rear ?

Afterthought: where is this single bleed screw situated ?

Ian Cornish

Edited August 8, 2023 by ianc

[stuart]

1 hour ago, ianc said:

I am puzzled - how does one ensure that all air is expelled from both left and right slave cylinders on a solid axle TR4A if there is but one bleed screw at the rear ?

Afterthought: where is this single bleed screw situated ?

Ian Cornish

Its on the right hand side. The front to back line goes into the left side then out to the other side. Thats where you would always start to bleed them. If you wind the back brakes up hard they actually bleed easier than an IRS car.

Stuart.

Edited August 8, 2023 by stuart

[Tr4aJim]

Yup, the front-to-back solid line goes to the LR wheel cylinder via a flex hose. However instead of a bleed screw in the LR cylinder, a solid line is attached there, that goes across the axle to the RR cylinder. That’s where the bleed screw is.

Jim

[ianc]

60 years of TR ownership, and one learns something new quite often on the Forum!  Thanks, Stuart & Jim, for the explanations.

Ian Cornish

[phil Dean]

When I had the Avenger that had a similar system 1 bleed screw on the back axle, I had to change diff (blew it) so bought a spare axle and made on good one from 2 decided to go with the older back plates to get away from stupid self adjusters that don't (self adjuster that is) had to change all the slaves cylinder from girling to lockheed and repipe the back brakes but the advantage was I then had a bleed nipple on both back brakes. Result a much better brake pedal with more feel to it.

 

Phil

[Terry Potter]

On 8/9/2023 at 8:36 AM, ianc said:

60 years of TR ownership, and one learns something new quite often on the Forum!  Thanks, Stuart & Jim, for the explanations.

Ian Cornish

Now you have puzzled me about 3 or 1 bleed nipple, I have 1 on each rear slave cylinder is there another one I should look for ? , I've managed to bleed all but still have a lot of play before break engages . If I pump pedal it seems better. HELP lol

[Tr4aJim]

Terry, the TR4 the IRS TR4A have bleed nipples at each corner. The solid axle TR4A has only three due to the way they had to modify the IRS pipe routing to fit the solid axle layout.

Jim

[Terry Potter]

5 hours ago, Tr4aJim said:

Terry, the TR4 the IRS TR4A have bleed nipples at each corner. The solid axle TR4A has only three due to the way they had to modify the IRS pipe routing to fit the solid axle layout.

Jim

Phew...lol.....I'll give it another go tomorrow,  weather permitting. 

[Rod Mac]

Disregard this if you don't have a brake servo, but I had a similar issue on my GT6 recently. Got an airlock in the servo. Topped up the m/c reservoir, ran a long bleed hose from closest wheel nipple (front right) to m/c reservoir (keeping the end under the fluid surface to create a short closed circuit), opened the bleed nipple and pumped the pedal. Out came the air trapped in servo and m/c.