Painting Things Black

With the bulk of the parts de-rusted with Deox-C, things are looking a lot more presentable. On some parts, the surface finish was still very rough, mainly on the front hub ‘cap’ and rear splash shield. To improve this finish, I gave them a quick sanding by hand. With some care, these surfaces looked a lot smoother and ready for painting.

Sanded and de-greased rear splash shield. Hanging and ready for painting.

Now that these parts are ‘de-rusted’, they need to be painted to protect the bare metal and to make them look nicer. I did some research into different paints before settling on POR 15 (Paint Over Rust) from Frost. I chose this paint mainly due to the vast number of previous builders/restorers who had used it, with barely any negative comments. Most blogs recommended buying only a small amount of this paint as it goes a very long way and some blogs even noted that if you are not very careful you can seal the lid to the can after one use. I guess this a testament to the strength of the paint itself. I, therefore, ordered 1 US pint of semi-gloss black from Amazon. When it arrived I realized I didn’t have any sacrificial paint brushes, although a quick trip to Wilko resolved this problem. 

Since the cleaning was done in stages whilst being stuck during the breakdown work, so, in turn, was the painting. However, rather than painting each part in turn once it had been cleaned, I collected a selection of parts together and painted them in one go. In the first round of painting I painted the following parts:

• Four Caliper carriers
• Two Rear splash shield
• Differential tie bar
• Different pendulum
• Differential bracket
• Two Front hubcaps

To ease the painting process, I tied most of the above parts to my garage door rails and wiped them down one last time with white spirit to remove any remaining grease. To avoid having permanent black blobs on the garage floor I placed plenty of newspaper below them.

Suspended parts ready for painting.

Some parts were too heavy to easily support from the rail (Pendulum and Differential tie bar) or did not have holes (front hubcaps) to attached them to the rail and so I placed these on newspaper on the floor.

Painted parts drying.

When it came to doing a second coat I discovered that despite having carefully cleaned the brush with lots of Fairy and white spirit, I must have left a small trace of the paint on the bristles because they went rock hard. After letting these parts dry/cure for about 5 hours, using another paintbrush I applied a second coat. I was very impressed with the finish of the paint and these parts. I wouldn’t say the parts were perfectly smooth but they are 20 years old after all. The gloss definitely builds up with each additional layer. 

Painted rear splash shield.

Painted caliper bracket.

Painted Differential Pendulum.

A few weekends later, once I had completed the strip down of the calipers, I continued the painting process. By this stage I had gathered together not only the brake components but also finished cleaning the front and rear hubs. These hubs didn’t need the Deox-C treatment, but instead a good wash in soapy water. 

Caliper and pistons in cleaned ready for painting. The slight surface rust on the calipers should not be a problem as POR15 is designed to be painted onto rusty surfaces.

Calipers and pistons ready for painting

To avoid paint getting inside the brake calipers I re-attached the cut sections of brake lines and reinstalled the bleed nipples. I then put a layer of electrical tape over the exposed bleed nipple to keep it clean. Further, I filled the main piston bore with newspaper and duct tape. The surfaces of the piston which sit inside the caliper should also not be painted so these were covered in a layer of black electrical tape (as shown in the above image).

To keep paint out of the internal surfaces of the hubs, these were also filled with newspaper and then a layer of duct tape. 

Front hubs cleaned and ready for painting.

The painting of these parts followed the same process as before, starting with a wipe over with white spirit and then two layers of POR 15.

Painted calipers and pistons.

Painted hubs.

With the painting of the donor parts, things are starting to look a lot of respectable and not just like a pile of rusty car parts. I can’t wait to get these on the chassis when it arrives.

Removing the Bearings and Races

With the front and rear hubs clean-ish, the next step is to remove the bearings, races and rubber seals. Given the potential age of these components, they will be replaced with new shiny parts.

The process to remove these components is very similar on the front and rear. The only differences are the size of races/bearings and the number of oil seals. Therefore, in this blog post I will document the process for a rear hub carrier, and briefly summarise the process for the front hubs.

Rear hub carrier prior to removing the bearings.

My first step was to review a schematic diagram of the rear hub, as firstly this illustrates which parts can be removed and how they are assembled into the hub carrier. Secondly, this diagram also shows which parts can be replaced and which parts cannot be bought separately and so require extra special care. I learned this second point the hard way, but more on that later. I have previously shown the excellent diagrams from JustJagUK, and their diagram for the rear hub carrier is below. The parts which need removing are the races and bearing (3 and 9 in the image below), the grease seals (2 and 10 in the image below) and inner spacers (4 and 5).

Schematic of rear hub from justjaguk.

I initially tried to remove the grease seals with some leverage from a flat headed screwdriver, with little success. I then placed a punch from the opposing side on the bearing and hit this with a hammer. With one or two good hits both the grease seal and the bearing popped out. This process was repeated on each grease seal/bearing without any problem. So far this was an easy job. The bearings don’t look in too bad a condition; however, they will be replaced as a matter of course. When removing the last bearing from the rear hub carrier two spacers fell out, one large and one small. These are specific to each hub carrier and so must be kept as a pair with a record of which hub they came from. The best way I found to mark these parts and the hub was to use a white cable tie to hold the spacers together and then place another white cable tie on the corresponding hub carrier. On the other side, I will use a black cable tie.

Hub carrier with grease seals, bearings and spacers removed.

The next step is to remove the races, which are a tight pressed fit. These are drifted out with a punch and a lump hammer. When Jaguar made these carriers they made a pair of opposing recesses in the internal sidewall in-between the two races. These recesses allow a punch to be placed against the back surface of the race so it can be drifted out with a hammer. Using these recesses and a few hits with the lump hammer the races start to move. To ensure the races stay square and slide out ‘more’ easily, ensure you alternate between the opposing reses.

Punch placed in reses to move inboard race.

One race has begun to move!

With many, many hits with a hammer later the races finally fall out. Whilst on paper this doesn’t appear difficult, it is a very time-consuming process with what appears like very slow progress.

The carrier is then turned over and the other race is removed using the same process. With both races removed, there should be 8 additional pieces on the bench; 2 races, 2 bearings, 2 grease seals and 2 spacers, to go along with the hub carrier. At this point do not bin the races or bearings as they will come in handy later on. 

Removed parts from hub.

The final parts of the rear hub carrier to disassemble are the fulcrum bearings. These are found at the bottom of the carrier, where the fulcrum shaft passes through, which secures it to a swing arm. To gain access to the bearings there is a metal washer and a grease seal which can be pried off with a flat head screwdriver. With one bearing removed, the other side bearing and central shaft will fall out, or at least they did in my case. 

Fulcrum shaft sand bearings removed from rear hub carrier.

From inspection, these bearings and races appear to be in good condition. There are no signs of rust or marks on the surfaces of the races. This is good news because the process of removing these races is a pain since there is no easy access beneath them. Since they seem to be in good condition, I will forgo the plan to remove and change these races and bearings. They now need a good clean, re-pack them with grease and ensure the same bearings go back into the same races. 

Fulcrum bearing race.

Front Hub

The front hub’s bearings and races are removed by a very similar approach, as is evident from the schematic below. The one thing to note is that when I removed my front hubs from the spline both the grease seal and the bearing came off and so I only have the races left to remove.

Schematic of the front hub from justjaguk.

The races are drifted out using the same approach as above. The front races come out far more easily than the rear ones … or maybe I am just getting better at drifting.  

The Cleaning Begins

Now that the bulk of the strip down is done, the next step is to clean, paint and service the parts ready for use on the new chassis. To minimize this work make sure to only clean the required parts, by reading through the AK manual (spot the rogue parts later on). I should say that whilst this blog article appears after all the strip down of the subframes is completed, in actuality due to being stuck at various stages (fulcrum shafts, separating the rear diff components to name just a few), this cleaning progress was done alongside the stripping down process.

As both of the front a rear brakes came off first, this entry will cover their cleaning, as well the initial stripping down of the calipers.

First Clean

With the bulk of the parts removed, the scale of the cleaning task ahead was very uninviting. To make this more fun and less like manual labor, I broke out the pressure washer. This should give all the parts an initial clean and degrease. Whilst this did not remove all the grease and grim it did remove the majority of the surface dirt/grim.

Originally dirty parts.

To avoid spraying dirt/grease everywhere, I needed a contained place to pressure wash these parts. So the day after our recycling bin was emptied, I turned it on its side, placed each part in turn inside and gave them a good spray. To aid the pressure washer I connected it up to a bucket with very soapy water. Given the color and quantity of grit which came out the upturned bin, this process certainly did something. With the parts sprayed, I left them on the drive to dry. With the warm summer this year, this did not take long.

Comparison of rear brake caliper before and after a pressure wash.

Pressure washed parts drying on the driveway.

Removing the Rust

The next stage of cleaning is to remove as much of the rust as possible. I don’t want to say I will remove all the rust, as at some point I would like to start building up the chassis. The rustiest parts which need to be reused are certainly the brake calipers (shown below). Whilst I could use a wire brush and/or a Dremel to clean these parts, this seems like a lot of effort, and I don’t have a Dremel. Luckily there is an easy chemical based option, which requires no more effort than placing these parts in a bucket of a chosen chemical solution.

Front brake calipers – initial condition.

Rear brake calipers with the carrier – initial condition.

After watching numerous rust removal product review videos on YouTube and reading other cobra blogs, I choose to go with Deox-C from Bilt Hamber. Weighing up the options on their website I chose to go for the 4 kg bag, rather than smaller bottles or the pre-made solution. This should give me plenty of rust removing solution without needing to reorder any.

Using this solution was easy, I mixed a 25% ratio of the powder to hot water in a 20 liter bucket. I then placed the complete caliper assembly and carriers into this solution. The Deox-C should not attack any of the rubber parts on the calipers, so no need to fully disassemble them at this point. However, I won't be re-using these rubber components anyway, so the point is mute. When placing the calipers into this solution, I ensured that the cut end of the brake lines stayed above the water line. This should avoid water getting into the brakes. 

Then 24 hours after placing the parts in the Deox-C bath I removed and inspected the chemicals hard work. The initially less rusty parts came out with a dark surface coating which easily washed off. With these parts rinsed, the metal looked in brand new condition, ready for painting (right hand side of image below).

Caliper with no rust left on it. Notice the black surface coating on the left-hand side which has been washed off the right-hand side.

The more rusty parts certainly look a lot better, and the regions which still had surface rust had now turned a bright orange color. Scrubbing these areas further removed a lot of the now loose surface rust, but it did not remove everything. These then went straight back into the Deox-C bath for another 24 hours.

Rear Brake caliper immediately after coming out from Deox-C bath.

Front brake caliper – still rusty after 24 hours and scrubbing.

I repeated this process of leaving the parts in the Deox-C bath for 24 hours and then scrubbing the surface to remove the loose rust. After 4 days all the parts came out clean. I did not change or replace the Deox-C during this period, which further adds to how impressed I am with this cleaner/de-ruster.

De-rusted caliper.

When finished, the magic solution appeared very black and had a lot of grey sediment sitting at the bottom. Reading the literature that came with the product, it says it is safe to pour down the drain, which I carefully did. I then rinsed the bucket out and also poured this down the same drain.

In addition to the large parts, I also had to clean a lot of the smaller nuts, bolts, handbrake shoe springs, and assorted clips. The process for these was the same, although instead of the large bucket, these were placed in a small jar with Deox-C. For such small parts, a single 24 hours was generally sufficient to remove the rust before being taken out scrubbed and rinsed. 

To keep track of these small parts, I bought a small bits box from TK-Maxx. Once each part was clean and dry, it got placed in this box, along with a label explaining where it had come from. This should prove invaluable later when rebuilding. 

Box of clean small parts, with labels.

At later stages, I also cleaned the pendulum, differential tie bar, and both front and rear hubs, although not discussed above since they followed the same process. The rear aluminium hub carrier (IRS) was dealt with separately and will be tackled in a future blog entry.

Disassembling the Brakes Calipers

With the brake calipers cleaned and de-rusted the next step is to break them down further into their component parts e.g. caliper and piston. Hopefully, this will now be a slightly cleaner job… although I doubt it will actually be clean! For me, this started with ensuring that all the bleed nipples and brake hoses could be loosened. The bleed nipples are all 9 mm nuts, which came off with a little careful force. The brake hoses have two different size bolt heads (15 mm on the front and 14 mm on the rear), but oddly, the internal threads of both are the same.

My next plan was to remove the brake piston and the rubber components. After a little research online I found two approaches; one is to pump the brakes whilst on the car and the other is to blow the pistons out with a compressed air line placed over the open hose line port. Since neither of these methods would work for me, I needed to come up with a different solution. 

To replicate a compressed air line, I decided to use a bicycle pump. However, in order to get sufficient air/pressure into the caliper, I have epoxied a football pump needle into one of the removed brake hose lines. I can then attach the needle end of the line to the pump and use the hose connector to attach it to the caliper, as normal. I did originally try without the epoxy, with just using multiple cable ties, but this did not give a good enough seal.

Bicycle pump connected to brake line with an epoxied needle.

 With the DIY tool connected to a caliper, I then placed a piece of wood in between the piston and the opposing side of the caliper to avoid the piston hitting the caliper and damaging itself. Then with two strokes on the pump, each piston in-turn popped out. Such an effortless job! Even though I might not need this section of hose again, it is defiantly a keeper.

Piston removed from caliper using DIY tool.

With the pistons out, they can be inspected for scratches and damage. Luckily they all appear to be in good order, with no scratches or marks below where the rubber boot sits.

The key lesson which I learned here from Ian, was to only ever use brake cleaner on the internals of these calipers, never WD40, or my favorite go-to cleaning product: white spirit. Luckily, I had already ordered a large spray can of this from Amazon. The internals of the calipers are then cleaned with brake cleaner spray. I found it helpful to also spray cleaner through both the bleed nipple and the brake hose port. I was surprised by the amount of gunk that came out of these internal sections.

Front caliper with piston and seals removed.

The piston itself is a story of two parts. The external surfaces of the piston were cleaned by rubbing them with a rag and brake cleaner to remove small imperfections and dirt. 

Cleaned front brake piston.

The internal part of the piston, however, was a lot rustier/dirtier. With delicate fingers and some sand paper, it was a quick job to get these internal surfaces looking considerably better and ready for painting.

Sanded internal surfaces of the front piston. 

The painting and re-assembly of these components are still to be tackled and so will come later.

Opening the Differential

In an earlier post, I mentioned I had an issue opening the differential cover due to the two large bolts which support the tie bar. After some head scratching, Ian came up with a perfect tool for removing these stubborn bolts. What's more, on his holiday travels to Finland he even found such a tool in a local hardware store, something none of my local tool stores stocked. The magic tool is a 30 mm slogging spanner, or in other words, a spanner designed to be hit with a hammer.

Differential with slogging spanner on the righthand bolt.

With the spanner placed around these bolts and many many hits with a lump hammer, this bolt finally began to loosen. With the bolt's removed, it is no surprise why it was such a pain to remove, given the large smooth concave contact area.

Complaining over though, the bolts did come out and with that, the differential cover fell away and I can at last check the internals. Upon opening the differential I was initially surprised that there was no paper gasket between the main housing and the cover, but Dr Google informed me that this is normal and instead a silicon gasket is used. Must make sure to add this to one of my future shopping lists.

First view of the opened differential – nice and oily.

Close up of the crown wheel.

After rotating the main crown wheel and inspecting these teeth along with the internal gears, everything seems to be in good order. There was no excess play in the output shafts.

Having had a precursory look, the cover can be placed back on with the smaller bolts which I took out last time. I will keep the large bolts out for now and give them a good clean before putting them back on.